Mirror : Was MI6 spy nuked?

Tuesday, September 07, 2010

Was MI6 spy nuked?

By Jon Clements | September 7, 2010

The body of murdered MI6 agent Gareth Williams is being examined for radiation poisoning as no obvious cause of death has been found.

The move comes as police began hunting a mystery Mediterranean couple who visited his block of flats weeks before his death.

Meanwhile, the 31-year-old's corpse will be tested for traces of chemicals such as Polonium 210 - used to murder exiled Russian secret agent Alexander Litvinenko in London in 2006.

Other poisons police are searching for include traces of cyanide, stricknine and even ricin, which Bulgarian agents used to murder dissident Georgi Markov in 1978 on Waterloo Bridge.

A postmortem has found no answers and toxicology tests unearthed no signs of alcohol or drugs in his system.

Police sources say there is no indication of radioactive poisons but investigators could not rule out anything.

Scotland Yard yesterday released CCTV footage of his last-known movements as he caught a Tube train on August 14 and shopped in Central London the next day. His naked corpse was found in a zipped and padlocked red North Face bag dumped in his bath on August 23.

Detectives believe the unidentified couple may have visited him at the apartment late at night in June or July. The man and woman, thought be aged 20 to 30, were buzzed in by entryphone at the communal front door but none of the neighbours knew them.

The couple are the only recent visitors to the address in Pimlico, Central London, believed to still be unaccounted for. One theory is they were acquaintances of the murdered agent who were unknown to his family or employers.

Tests have shown there were no marks on Mr Williams' body, no signs of forced entry or disturbance at the property and nothing was stolen. The Cambridge-educated maths genius had returned home on August 11 from a holiday in the US.

He had often flown to the States on top secret work visiting the National Security Agency's eavesdropping HQ. Over the next few days back in London he was captured on CCTV at Holland Park Tube station in West London, dressed in a red T-shirt and clutching a shopping bag. The last camera sighting of him was on August 15, when he went into Harrods in Knightsbridge and walked towards nearby Sloane Street, near a Dolce and Gabbana store.

Police found his body on the afternoon or August 23 after being alerted by MI6 staff when he failed to turn up to work.

Det Chief Insp Jacqueline Sebire, leading the investigation, said: "I would appeal to anyone who may have seen or had contact with Gareth between August 11 and 23 to come forward. This remains a complex, unexplained death enquiry."

Russian exile Mr Litvinenko collapsed on November 1 four years ago after drinking from a cup of tea spiked with Polonium 210 while meeting two former KGB secret service men at a hotel in London.

Doctors were initially mystified about the cause of his illness. They wrongly believed it was rat poison until advanced tests identified the rare radioactive isotope.

Mr Litvineko died on November 23 from heart failure after suffering agonising stomach pains. Six months later UK prosecutors announced that former KGB agent Andrei Lugovoi should be charged with murder. Russia will not extradite him.

~~~

POLONIUM

Named after Poland. Just 0.1 microgrammes - equal to one-ten millionth of an aspirin pill - would be fatal.

Daily Record : Pathologists test for radioactive poisons in blood of MI6 spy found dead padlocked in bag

Tuesday, September 07, 2010

Pathologists test for radioactive poisons in blood of MI6 spy found dead padlocked in bag

September 7, 2010

DETECTIVES probing the mystery death of an MI6 codebreaker are looking for radioactive poisons.

Gareth Williams, 31, was found naked in a padlocked sports bag at his London flat.

Scotland Yard confirmed that detailed tests had found no traces of drugs, medicines or even alcohol in his blood.

An earlier postmortem found no marks on Mr Williams and no signs of a disturbance at his flat near MI6 HQ.

Police now want forensic scientists to search for rare poisons - including polonium 210, used to kill former KGB agent Alexander Litvinenko.

Sources said there is no suggestion yet that radioactive substances were involved.

Police found Mr Williams on August 23 when he failed to report for his top secret work.

Detective Chief Inspector Jacqui Sebire said: "This remains a complex, unexplained death inquiry".

Litvinenko died after drinking a cup of tea spiked with polonium 210 while meeting former Russian agents in London in 2006.

Newsweek (blog) : Mystery Surrounding Death of U.K. Code Breaker Deepens

Tuesday, September 07, 2010

Mystery Surrounding Death of U.K. Code Breaker Deepens

by Mark Hosenball | September 7, 2010

A statement released by Scotland Yard on Monday and posted on the website of the London Metropolitan Police Service reveals more details about the peculiar death of Gareth Williams, a 31-year-old mathematics wizard who worked for Britain's electronic eavesdropping agency, Government Communication Headquarters, but sheds no light on possible causes. Officials on both sides of the Atlantic acknowledge that at the moment, they have no hard information—and no real leads—to explain the bizarre circumstances in which Williams' body was found late last month in an apartment not far from the headquarters of MI-6, Britain's foreign intelligence service, where he for the last year had been on temporary assignment.

The statement describes how Williams' body was discovered by uniformed London bobbies in his apartment—possibly an MI-6 "safe house," depending upon which British media account you believe—in the posh Pimlico neighborhood about half a mile from MI-6 on Aug. 23. The police account describes the exceptionally strange circumstances in which the body was discovered: He was "found unclothed, in a zipped and padlocked red North Face holdall which was in an empty bath," Scotland Yard said.

The police account notes that there was no sign of forced entry into the apartment, "and no signs of disturbance inside. …We do not believe there is any property missing from the flat. There is no suggestion the items within the flat were specifically posed. No drugs, or indications of drug usage were recovered."

The police statement also notes that an autopsy conducted on Aug. 25 "established no obvious cause of death." The police account says that extensive forensic examinations of the Pimlico apartment and of samples taken from Williams' body during the autopsy continue, but adds that "Initial indications from the toxicology examinations show no trace of any alcohol or routine or recreational drugs."

In the statement, the police say they have confirmed that Williams, who had been on a "planned holiday in the U.S.," had returned to London on Aug. 11; video from London's wide-ranging closed-circuit video surveillance network shows him shopping after his return in well-known London retail districts. Police say they are appealing to the public for information to help identify a man and a woman who turned up late one evening at Williams' building on an unspecified day in June or July. The cops say that the couple, who were admitted to the building through the "communal front door," were between 20 and 30 years old and were both of "Mediterranean appearance." But the statement offers no other clues as to their identity, nor any further indication as to what, if any, evidence the authorities might have to link them to the dead man.

British media have been gorging themselves on ever more baroque theories about what's behind the case. A story in the Daily Mail, one of London's most aggressive tabloids, offers a menu of conflicting speculations for possible perpetrators, ranging from Islamic or Irish terrorists to Russian spies or some sinister connection to Williams' personal life. Following the widespread publication of pictures showing a svelte Williams in a tight-fitting cycling uniform, some stories suggested a possible connection with London's gay scene, noting that at least one of London's best-known gay bars was located not far from MI-6 headquarters on the South Bank of the river Thames. Williams' family has denied that he was gay.

Among the few undisputed issues in the case are certain basic facts about Williams' background. Most accounts describe him as a youthful mathematics expert and keen cyclist who was permanently assigned to GCHQ, Britain's version of the American code breaking and eavesdropping National Security Agency, but who was just about to complete a one-year temporary assignment at MI-6 headquarters in South London.

Some accounts suggest that as part of his work for GCHQ, he made periodic trips to the headquarters of both the CIA and NSA, and that the American agencies were deeply concerned about his death. However, U.S. officials have denied British media reports that the CIA is now investigating the case, and there is little indication that the FBI or the U.S. Justice Department are in any way involved. (As is its customary practice, the N.S.A. declined to offer any comment on the case.)

Apart from the latest police statement confirming that before his death, Williams had been on vacation in the U.S., there is no confirmation that he ever paid visits—official or unofficial—to any U.S. intelligence headquarters. Moreover, several U.S. officials who should have been briefed if there was any concern inside U.S. agencies that Williams' death somehow involved the compromise of U.S. or U.K. spy secrets say that they have been given no information about the case whatsoever. Knowledgeable officials on both sides of the Atlantic do stress, however, that at this point, whatever mysteries the case does appear to present, there is no evidence that Williams was involved with a spy unit other than the British agencies that employed him, and therefore no evidence suggesting he was a double agent.

Wales Online : Police hunt for couple seen near murdered spy’s flat

Tuesday, September 07, 2010

Police hunt for couple seen near murdered spy’s flat

by Darren Devine, Western Mail | September 7, 2010

DETECTIVES probing the death of Welsh spy Gareth Williams yesterday revealed they are hunting a man and woman of “Mediterranean appearance”.

A Scotland Yard spokesperson described the pair, aged between 20 and 30, as “potential suspects” over the murder of the code breaker.

The two were let into the communal entrance of Mr Williams’ flat in Pimlico, central London, late one evening in June or July.

His decomposing naked body was found padlocked shut in a holdall in a bath in the top floor flat by officers who broke in on August 23 after Mr Williams failed to appear at work for several days.

Yesterday officers released CCTV footage of him as they appealed for the public’s help.

It showed the 30-year-old, from Valley, Anglesey, entering Holland Park Underground station about 3pm on Saturday, August 14.

Police said post-mortem examinations found “no obvious cause of death” and initial indications from toxicology tests showed no trace of any alcohol or routine or recreational drugs.

A force spokesman added there was no sign of any forced entry to his flat in Alderney Street or disturbance inside, and no property was believed to be missing.

Mr Williams, who worked at Government listening post GCHQ, was days from completing a one-year secondment to the headquarters of the Secret Intelligence Service, MI6, in Vauxhall, London.

Police said Mr Williams had returned from a planned holiday in the United States on August 11, and went shopping “on a number of occasions” in the West End and Knightsbridge areas.

On August 15, he went to a cash machine and then to Harrods before CCTV images show him in Hans Crescent, heading towards Sloane Street, near a Dolce and Gabbana store, at about 2.30pm.

Police said Mr Williams, who was 5ft 7in and of muscular build with short hair, was wearing a red T-shirt, beige trousers and white trainers.

Detective Chief Inspector Jacqueline Sebire, who is leading the inquiry for the force’s homicide and serious crime command, said: “I would appeal to anyone who may have seen, or had contact with Gareth in the period between 11th and 23rd August to come forward and speak with us.

“This remains a complex unexplained death inquiry.”

Though his body was found more than a fortnight ago scientists have, as yet, been unable to establish a cause of death.

And despite police referring to an “unexplained death”, Home Office forensic pathologist Dr Brian Rodgers said the circumstances suggest it was “clearly a homicide”.

Dr Rodgers, who has worked on high-profile murder investigations in North Wales, said aside from cases where someone has died of injuries such as stab or gunshot wounds, establishing a cause of death was more complex in a decomposing corpse.

He suggested Mr Williams may have been poisoned or strangled with a necktie as a pathologist would have problems establishing this on a decomposing body.

Dr Rodgers said: “The difficulty with any body that’s decomposing is that some of the subtle signs of certain modes of death can be very difficult to ascertain – like asphyxia with a ligature.”

Dr Rodgers, 57, who works part-time at Ysbyty Glan Clwyd in Bodelwyddan, Denbighshire, added: “What you have to remember is that from the process of decomposition chemicals are produced in the body which can affect the analysis of various poisons, so you’d get false positive and negative results.

“I don’t know anything about the case other than what I’ve read in the papers and has been on the news, but I suspect he’s either been poisoned or strangled in some way.”

In a statement shortly after his body was found, Mr Williams’ parents Ian and Ellen hit out at rumours that suggested the codes expert was involved in risky sexual practices, saying they had been “very distressing”.

In tribute to him they said: “Gareth was a generous, loving son, brother, and friend, and he was a very private person.

“He was a great athlete, and loved cycling and music.

“His loss has devastated us and we would ask anyone with information to come forward and assist the police inquiry.”

WorldNetDaily : Rattled: Intel community reacts to sudden death

Tuesday, September 07, 2010

Rattled: Intel community reacts to sudden death

Body of computer expert found inside locked case in apartment

September 7, 2010

Whether Gareth Williams was at the wrong place at the wrong time or he was targeted by a network of foreign interests who wanted him out of their way, the government employee's death is raising alarms in the United Kingdom, according to a report from Joseph Farah's G2 Bulletin.

That's primarily because of his job on the cutting edge of computer technology at the Government Communications Headquarters, a sprawling organization with its fingers in dozens, perhaps hundreds, of stealth projects.

The investigation after Williams' body was found in a large locked sports bag in the bathroom of his apartment has been unprecedented, with MI6, MI5 and Scotland Yard's murder squad on the case.

The cause of his death hasn't been confirmed, but sources report poison, shooting and knifing largely have been eliminated. The Russian SVR and the Chinese Secret Intelligence Service remain in the circle of suspicion. Some reports allege he was a double agent, and there is speculation he was killed because he refused to cooperate with foreign interests.

Staff members at GCHQ, where doors simply are marked "No Admission," have been left stunned.

Williams worked in computer technology, using his mathematical abilities in the fight against terrorism and cyber warfare. He had come into the service of his country after finishing at Cambridge.

© 2010 WorldNetDaily

Washington Post (blog) : Gareth Williams probe focuses on mystery couple

Tuesday, September 07, 2010

Gareth Williams probe focuses on mystery couple

By Jeff Stein | September 7, 2010

London police, still stumped by the bizarre death of British code-breaker Gareth Williams last month, are looking for a young couple "of Mediterranean appearance" who were recorded by security cameras while visiting his building late at night in the weeks or months before he died, according to local reports.

Police have also been studying tapes from London’s closed-circuit security cameras that reportedly recorded Williams shopping in London’s fashionable Sloane district in the days before his decomposing body was discovered in an athletic bag in his apartment.

An autopsy discovered no drugs or alcohol in his system, said police, who were also investigating whether anyone made a duplicate of Williams’s keys.

An expert on the National Security Agency, meanwhile, speculated that Williams was working for the Special Projects Activity, a little-known clandestine unit buried deep in the U.K.’s General Communications Headquarters, Britain’s equivalent of the NSA.

The SPA and its American equivalent, a joint CIA-NSA operation known as the Special Collection Service, conduct ultra-sensitive operations against foreign targets from U.S. and allied embassies abroad.

Williams, a “gifted mathematician,” according to news reports, frequently visited NSA headquarters at Ft. Meade.

“All the people I talk to say Williams was probably involved in what is referred to in the intelligence trade as ‘technical operations,’ which is a broad cover-all term which generically refers to clandestine signal intelligence or telephone tapping, things like that," Matthew M. Aid, author of "The Secret Sentry: The Untold History of the National Security Agency," said in a telephone interview.

“The targets of the clandestine special collection units include the cell phone communications of (foreign) government ministers, police officials, military commanders (and) … security teams that are following (our) intelligence agents around the city,” added Aid, a onetime Russian linguist with the NSA’s Air Force branch.

The synergy of American and British eavesdroppers, Aid and other NSA historians say, is particularly valuable to U.S. intelligence, if only because the U.K. (and other English-speaking allies, such as Canada, Australia and New Zealand) have embassies -- and thus listening platforms -- where Washington doesn’t, such as in Iran and North Korea.

The NSA supplies the allies with advanced interception and code-breaking equipment, they say, and gets to share the take in return.

Daily Post : CCTV images of murdered spy Gareth Williams released

Tuesday, September 07, 2010

CCTV images of murdered spy Gareth Williams released

by Eryl Crump, Daily Post | September 7, 2010

Images of the last known sightings of murdered MI6 spy Gareth Williams before his body was discovered padlocked in a holdall have been released.

The CCTV images have been released by police as part of an appeal for information into the death of the 30-year-old from Valley, Anglesey.

They show Mr Williams out and about in London on the weekend of August 14/15. His body was found in a bag in the bath of his central London flat nine days later.

The first footage shows him entering Holland Park tube station in west London at about 3pm on August 14. A second bit of film shows him on the following day shopping in west London around the Brompton Road area and going into Harrods.

Detective Chief Inspector Jacqueline Sebire, who is leading the inquiry, said Mr Williams had returned from a planned holiday in the United States on Wednesday August 11 and went shopping “on a number of occasions” in the West End and Knightsbridge.

On Sunday August 15, he went to a cash machine and then to Harrods before CCTV images show him in Hans Crescent, heading towards Sloane Street, at about 2.30pm

Ms Sebire said: “I would appeal to anyone who may have seen or had contact with Gareth between August 11 and 23 to come forward and speak with us. This remains a complex unexplained death inquiry.”

Detectives said they were also trying to trace two people seen near the code-breaker's flat.

Ms Sebire said officers want to identify a man and a woman, both of Mediterranean appearance and aged between 20 and 30, who were let into the communal entrance of Mr Williams’ flat in Pimlico late one evening in June or July.

His body was found by officers who broke in after Mr Williams failed to appear at work for several days.

Post mortem examinations found “no obvious cause of death” and initial indications from toxicology tests showed no trace of any alcohol or routine or recreational drugs. Testing for any other substance is ongoing.

Ms Sebire said there was no sign of any forced entry to his flat in Alderney Street, no signs of disturbance inside, and no property was believed to be missing.

“There is no suggestion the items within the flat were specifically posed,” she said.

Mr Williams was days from completing a one-year secondment to the headquarters of the Secret Intelligence Service, MI6, in London.

His horrified family have paid tribute to him describing him as a “generous, loving son, brother and friend”.

A keen cyclist, Mr Williams often visited his family, who live at Valley near Holyhead, and often took part in events organised by Holyhead Cycling Club and Clwb Rasio Mona.

His family have hit out at rumours suggesting he was involved in risky sexual practices, saying they had been “very distressing”.

In a statement they said: “His loss has devastated us and we would ask anyone with information to come forward and assist the police inquiry.”

Police urged anyone with information to contact the incident room on 0208 358 0200 or call Crimestoppers anonymously on 0800 555 111.

Express : SPY DEATH POLICE INQUIRY LEADS TO MYSTERY COUPLE

Tuesday, September 07, 2010

SPY DEATH POLICE INQUIRY LEADS TO MYSTERY COUPLE

September 7, 2010

A MYSTERY couple were being sought last night by detectives investigating the bizarre death of an MI6 spy.

The man and woman, of Mediterranean appearance and aged 20 to 30, called at codebreaker Gareth Williams’ home shortly before he died.

They “were buzzed” through the communal front door and into the converted Georgian town house in Pimlico, central London. It is not known if they visited the spy’s top-floor flat.

Details of the couple emerged as police released the last known images taken of Mr Williams, 31, before his body was found on August 23 inside a padlocked sports bag dumped in his bath.

The CCTV footage shows him in London on ­Saturday, August 14, and Sunday, August 15, shortly after he returned from a holiday in the US and eight days before his body was discovered.

As police appealed for help to piece together his last movements, there was renewed speculation that the brilliant mathematician had been poisoned or suffocated. ­Scotland Yard has not ruled out the possibility he was assassinated by a rival intelligence outfit.

Initial toxicology tests showed no trace of ­alcohol or drugs. There were no signs of forced entry or a disturbance and nothing appeared to have been stolen from inside the flat.

It is believed further scientific analysis is being carried out on the body to detect tiny traces of radioactive or other toxic materials.

Detective Chief Inspector Jacqueline Sebire said: “I would appeal to anyone who may have seen, or had contact with Gareth between August 11 and 23 to speak to us on 0208 358 0200, or to remain anonymous, Crimestoppers on 0800 555 111.” She added: “This remains a complex unexplained death inquiry.”

Sun : Cops hunt couple over MI6 murder

Tuesday, September 07, 2010

Cops hunt couple over MI6 murder

By MIKE SULLIVAN, Crime Editor | September 7, 2010

SCOTLAND Yard was last night hunting a mystery couple over the murder of body-in-the-bath MI6 spook Gareth Williams.

The man and woman called at the codebreaker's flat in the dead of night weeks before the 30-year-old was found killed.

A neighbour who let the pair into their central London block described them as Mediterranean-looking.

Detectives have so far been unable to trace the couple. They appealed to the public for help - as they issued CCTV of the victim's last known movements.

Eight days later a holdall was found in his Pimlico bath with his body stuffed inside.

How he died remains a mystery. A toxicology report revealed by cops yesterday found no alcohol, drugs or easily-detected poisons in his blood.

Experts are carrying out further tests to discover if he was the victim of any rare poisons - like the radiation that killed former KGB spy Alexander Litvinenko in London in 2006.

But the main focus of the police inquiry is on the Cambridge graduate's private life.

Det Chief Insp Jacqueline Sebire said: "This remains a complex unexplained-death inquiry."

News dot com [AU] : Dead British spy Garreth Williams 'had no drugs, alcohol in system'

Tuesday, September 07, 2010

Dead British spy Garreth Williams 'had no drugs, alcohol in system'

September 7, 2010

SCOTLAND Yard detectives said last night an autopsy has revealed no traces of drugs or alcohol in the body of MI6 spy Garreth Williams.

Police also confirmed no traces of drugs or alcohol were found in the reclusive spy's flat in central London.

Williams, a decoder for the British secret service, was found dead in his flat last month.

His naked body was padlocked in a red North Face holdall and in an empty bath in his en suite bathroom when it was discovered.

Police want to speak with two people who were seen on CCTV footage entering the communal door of Williams' flat in June or late July.

They have also released images of Williams last days, where he was caught on CCTV cameras shopping in London's West End and the exclusive Harrod's department store in Knightsbridge.

An autopsy last month failed to establish a cause of death.

Police said nothing was stolen from the flat and there were no drugs, or indications of drug usage in the flat.

They have appealed for witnesses who may have seen Williams in the weeks leading up to his death.

Detective Chief Inspector Jacqueline Sebire said: "This remains a complex unexplained death inquiry."

Daily Star : MI6 MURDER: COPS HUNT 'MEDITERRANEAN COUPLE'

Tuesday, September 07, 2010

MI6 MURDER: COPS HUNT 'MEDITERRANEAN COUPLE'

By Gemma Wheatley | September 7, 2010

POLICE last night revealed they are looking for a “Mediterranean couple” over the death of MI6 spy Gareth Williams.

The news came as detectives released some of the last pictures of the murdered agent alive.

Gareth Williams' naked body was found padlocked inside a suitcase at his £400,000 flat in London’s Pimlico on August 23.

He was last seen shopping in Harrods eight days earlier, on Sunday August 15.

And police have released CCTV images of him entering Holland Park Underground station the day before.

The Met yesterday revealed it is trying to trace a man and woman who were spotted visiting Mr Williams’s flat late one evening a few weeks earlier.

A spokesman for Scotland Yard said: “Officers are appealing for information to identify a man and a woman, both of Mediterranean appearance, aged between 20 and 30 years old, who called at 36 Alderney Street in June or July, late one evening.

“They were let into the communal front door.”

There were no signs of disturbances in the flat or of a forced entry and nothing is believed to have been taken from inside.

The new clues came as it also emerged that his body had been found submerged in a mystery fluid, thought to have been used to speed up decay.

The fluid was not believed to be blood or water and could have been used to complicate toxicology results.

Mr Williams’s remains were found stuffed inside a North Face sports bag in his bath.

The 31-year-old cycling and fitness fanatic was a maths genius on secondment to MI6’s HQ on the bank of the Thames in London when he died.

His last movements are believed to have been on Sunday, August 15, when he was seen shopping in the capital’s Brompton Road.

Police said Mr Williams, who was 5ft 7in and of muscular build with short hair, was wearing a red T-shirt, beige trousers and white trainers.

He withdrew money from a cash machine and went into Harrods.

At around 2.30pm he was spotted heading from there towards Sloane Street.

Forensic tests at his flat are continuing, while results from the post-mortem examination revealed that there were no indications of drug use.

But so far police are no closer to finding out exactly how Mr Williams died.

Det Chief Insp Jacqueline Sebire, who is leading the investigation, said: “I would appeal to anyone who may have seen or had contact with Gareth in the period between 11 and 23 August to come forward and speak with us.

“This remains a complex unexplained death inquiry.”

Last night, University of Buckingham security expert Professor Anthony Glees said: “In my own opinion, a murder of this kind bears all the hallmarks of a professional killing and not a rage attack.

“It looks increasingly to me that a hostile intelligence service was responsible.

“To me this looks like a Russian job – they have killed in London before – but it could also be an Iranian one.”

Daily Mail : Was it poison? Two weeks after murdered spy was found in his bath, baffled police release CCTV of victim as they probe radiation theory

Tuesday, September 07, 2010

Was it poison? Two weeks after murdered spy was found in his bath, baffled police release CCTV of victim as they probe radiation theory

By Charlotte Gill | September 7, 2010

Tests to discover whether murdered MI6 spy Gareth Williams was poisoned are being carried out.

Yesterday, detectives revealed pictures of the last known moments of the 31-year-old codebreaking expert.

They also disclosed that his body was naked when found and initial toxicology tests show no traces of alcohol or recreational drugs in his system.

With no obvious cause of death, further tests are under way to determine whether a rare drug or poison can be found.

One possibility is that Mr Williams was killed by radiation poisoning, as happened when Polonium 210 was used to murder exiled Russian secret agent Alexander Litvinenko in London in 2006.

CCTV images show him walking through some of London’s most affluent areas eight days before his body was found padlocked in a sports bag in his bath.

Detectives also appealed for help in identifying a young man and woman who called at his flat late one night.

The pair, both of Mediterranean appearance and aged between 20 and 30, were let in through the communal door to the Victorian house conversion weeks before he died. It is not known whether they went to his flat or indeed saw the spy – deepening the mystery over his murder.

Two weeks after the spy’s body was found police are still unable to say how he died.

The CCTV footage shows him shopping alone at Harrods on Sunday August 15 at about 2.30pm. He is in a red T-shirt, beige trousers and white trainers and is carrying a white plastic bag.

A day earlier he was caught on CCTV entering Holland Park Tube station in West London at a similar time, again by himself, wearing the same clothes and carrying a white bag.

Scotland Yard said there was no sign of forced entry to Mr Williams’s flat, suggesting he might have known his killer and had let them in.

Detectives will not go into detail about who let the mystery couple in through the front door of the house in Pimlico, Central London, ‘late one evening’ in June or July or why they were there.

But the incident is seen as a potentially significant line of inquiry in the increasingly puzzling case, with pathologists yet to determine how the cipher and codes specialist died.

Although there are no outward signs that the cycling enthusiast met a violent death, officers have not yet ruled out asphyxiation.

The revelation that his body was naked will fuel speculation that he could have been involved in a sex game which went wrong.

Another theory for the absence of clothes is that his killer was forensically aware and wanted to destroy any potentially incriminating contact with Mr Williams.

Sources close to the inquiry have admitted they are ‘baffled’ about the case.

Claims that Mr Williams had previously complained of being followed and that a laptop computer is missing from his home have been rejected by police.

Detective Chief Inspector Jackie Sebire, who is leading the inquiry, said: ‘This remains a complex unexplained death inquiry.’

Investigators know that Mr Williams, who was a loner with few friends, returned from a ‘planned holiday’ in the U.S. on Wednesday August 11.

He was coming to the end of a year-long secondment at MI6, whose headquarters are half a mile from his flat, and was due to return to GCHQ, the Government’s listening post in Cheltenham.

Using his mobile phone to track his whereabouts, they have discovered by trawling through CCTV that he went shopping ‘on a number of occasions’ in the West End and Knightsbridge on August 14 and 15.

After visiting Harrods, he seen walking towards Sloane Street, near to the Dolce and Gabbana store, though he does not go in the shop. Police have refused to disclose what he was buying.

It is the last time he was seen and detectives are still desperate to find any further sightings.

Lurid speculation that Mr Williams was a gay transvestite and bondage gear was found in the flat has been dismissed as untrue by police.

A source close to the inquiry has also said there was ‘nothing out of place in his finances’ despite reports that unexplained money might have moved in and out of his account.