It is exactly 15 years since MI6 spy Gareth Williams tragically died at the age of just 31.

On August 16 2010, in one of the most mysterious and bewildering deaths ever on British soil, police said he impossibly folded himself inside a red North Face holdall in his bath.

His Pimlico bathroom was spotless and officers found no evidence of Gareth’s fingerprints on the padlock of the bag or even the rim of the bath that the bag was found in.

Detectives found no signs of struggle and no bruises or marks on his body. The heating was on full blast – despite being the height of summer – the bathroom door was shut, the shower screen closed and the lights were switched off.

The Welsh prodigy, considered a puzzle-solving genius, had been scooped up by GCHQ having completed his GCSEs in primary school, A-levels at 13 and his maths degree at 17. But the solution to the puzzle surrounding his own death, remains unsolved.

MI6 had failed to notice that one of its analysts was missing from work and his spymasters only investigated his absence on August 23 after a call from his panicked sister.

Gareth was then found serenely inside the bag, his hands neatly folded on his chest in an almost religious pose. The zip had been padlocked on the outside but the key to the lock was lying beneath his right buttock.

Just eight days earlier he was seen happy and healthy on CCTV, buying cakes from Harrods and steaks from Waitrose. 24 hours later he was dead in his home Alderney Street in Pimlico – half a mile from MI6’s headquarters on Vauxhall Bridge.

Twice police have closed criminal investigations into his death, even though his inquest concluded he had been ‘killed unlawfully’, probably before he was put neatly in his bag.

Detectives instead claimed they believe he was alone when he died and it was probably a tragic accident related to sex. Cash, unworn women’s designer clothing and a wig were found in the flat along with his, and a mystery man’s semen.

Gareth Williams was caught on CCTV at Holland Park Underground station on 14/8/2010 in one of the final images of the MI6 maths genius. He died the following day and was discovered at his Pimlico flat on 23/8/2010

Peter Faulding attempts to lock himself inside a holdall. He failed to do this 300 times. He says it was impossible to do without leaving prints or DNA, but the police said otherwise claiming it was possible and Gareth probably died in a tragic accident. He claims officers asked him to change his statement

Gareth’s parents have long asked for privacy as they continue to grieve their beloved son.

The case has been branded a whitewash and Peter Faulding, a world-leading confined space rescue and forensic search specialist, who tried 300 times to get in the same sized bag and concluded: ‘Even Harry Houdini himself wouldn’t have managed it’.

Peter recreated the scenario as he helped the Met investigate the so-called Spy in the Bag case in 2010 but while detectives closed the criminal case, he is convinced that Gareth was murdered and there was a ‘cover-up’ by police and the secret services.

Mr Faulding has today claimed to the Daily Mail, for the first time, that he was asked by police to change his statement – but he refused.

‘Gareth Williams should have been commended for his work with the security services not tarnished as a cross dresser. They just wanted to bury this case and leave Gareth’s name being tarred’, Mr Faulding told the Mail on the 15th anniversary of his death.

‘My belief is that the bag was placed in the bath with Gareth dead already. No one in their right mind believes he was on his own. It is a physical impossibility.

‘I had paramedics on standby and a knife on a string hanging around my neck to cut myself out. I could zip myself in but could not do up the padlock. Another yoga expert tried’.

After trying hundreds of times to climb in, zip up the bag and lock it from the inside without leaving fingerprints on any surfaces, Mr Faulding concluded with certainty that Gareth could not get into the North Face bag alone.

He was then invited to meet with senior investigating officers from the Metropolitan Police at the Wyboston Lakes National Crime and Operations Faculty.

He said that a senior investigating officer told him in a meeting: ‘You have probably seen that a 15-year-old girl has successfully climbed into a bag and zipped herself in. I would like you to rewrite your statement to acknowledge it can be done.

‘I stood up and said “I am not playing your games”, walked back to my helicopter parked on their fields and flew home’.

He said: ‘I have never spoken about this. But after the Nicola Bulley case, I realised things get covered up’.

Mr Faulding is convinced that the lack of ‘trace evidence’ – such as DNA and finger prints as well as footprints – means Gareth was murdered.

‘He was naked. The lights were out, the door closed, the heating was on full, the shower screen closed. Just back from a bike ride, he would have had to walk into the bathroom in the dark and closed the shower screen’, Mr Faulding said.

‘That alone would leave his marks all over the floor, light switch, footprints and fingerprints on the glass shower screen.

‘Then he would have to climb into the bag close the zipper and the padlock from the inside, leaving more marks on it’.

Mr Faulding, who was the same height and build as Gareth, tried to get himself in the same kind of bag hundreds of times. A leading yoga expert also did it – but also failed.

He later gave evidence at the inquest and is absolutely clear that it is not credible to believe Gareth did it alone. The coroner found she was ‘satisfied that on the balance of probabilities that Gareth was killed unlawfully’.

Mr Faulding said: ‘The coroner Dr Fiona Wilcox asked me what I thought happened. I said with respect I am not here as a detective. She said: “You have a very impressive CV and I would like your honest opinion.

‘I told her that I believe Gareth was murdered. I turned towards his family in court. They looked at me and mouthed “thank you” with gratitude and validation’.

Gareth on the Tube in the hours before his death

A forensic review by Scotland Yard found that ‘no new DNA’ was found, therefore it was more likely that Williams was alone when he died

A Metropolitan Police handout photo of the interior of Gareth Williams’ flat after his death. The heating was on full blast – despite being the height of summer – the bathroom door was shut, the shower screen closed and the lights switched off.

Mr Williams’s naked body was found inside a holdall – which was padlocked from the outside – in the bath of his flat (above) in Pimlico, central London, in August 2010

A police image of a representation of the lock on the red sports bag that Gareth Williams body was discovered in at his flat. Police claimed he locked it from the inside and the key was under his body

Williams was found in north face holdall, padlocked together. There were no fingerprints found on the bag, padlock or bath and the key to the padlock was found inside the bag, underneath Williams body

The Welsh maths prodigy after completing his GCSEs at 10, A-Levels at 13 and then getting a first-class degree from Bangor University at just 17.

He was discovered by Government Communications Headquarters (GCHQ) while doing a PhD in Mathematics at the University of Manchester, and brought on board as a codebreaker.

He worked at the headquarters there in Gloucestershire, before his secondment to MI6 in London to work as technical support on a highly sensitive operation.

Williams was last seen alive buying cakes in Harrods and peppered grilled steaks in Waitrose. That same evening he had also planned to meet a colleague.

The next day he had been expected to chair a MI6 meeting having just returned from a hacking conference in Las Vegas.

Despite this, MI6 only investigated his absence more than a week later, on August 23, after a call from his sister.

At the time theories surrounding his death ran wild, from sex games gone wrong to a targeted assassination by a hostile state.

Peter Faulding ruled out MI6 involvement, telling the Mail today: ‘If the service got rid of Gareth it wouldn’t be in a bag in the bath for the world to see’.

Coroner Fiona Wilcox concluded in 2012 that the plethora of unanswered questions, a lack of a struggle and the Houdini-standards contortionism needed to get inside the bag and lock it alone, without leaving any prints, all pointed to a ‘third-party involvement’, calling Gareth’s death ‘criminally mediated’ and ‘unlawful’.

But in 2013, after a three-year investigation by Scotland Yard, its detectives concluded the opposite and said there was no evidence of anyone else in the flat and that Gareth probably died alone as a result of somehow accidentally locking himself inside the bag.

The case was reopened in 2021 to allow for a new forensic investigation using more modern technology on items of ‘significant’ interest such as a towel. But despite a bewildering lack of answers about what happened in the so-called ‘Spy in the Bag’ case, the Met again closed its investigation last year after it found ‘no evidence’ that disproves their main theory that he was alone.

There were no new findings of DNA, nor that a third party was present at the time of Williams’ death, Scotland Yard said.

Bewildering questions on how and why it happened, many armchair detectives have theorised that the 31-year-old, an expert on mobile phones, may have been murdered by a foreign state or even Russian Mafia because of his work investigating money-laundering networks.

He was not believed to be in a relationship at the time of his death, however during the investigation six boxes of unworn women’s designer clothing worth £20,000 and a orange wig were found in the apartment.

MI6 spy and maths genius Gareth Williams was 31 when he was found dead in  a bag  in his flat in Pimlico, central London in 2010.  Police claim he acted alone and it was probably a tragic accident

Mr Williams’s family have long suggested foul play, with two police sources claiming some of Williams’ work was focused on Russia – and one confirming reports he had helped the US’s National Security Agency trace international money-laundering routes used by organised crime groups including Moscow-based mafia cells.

But police confirmed that there is no criminal inquiry, no suspects and no new evidence.

MI6 colleagues said he was a ‘quiet bloke’ who ‘got on with his work’. ‘When he had a drink with work colleagues, he had an orange juice and left.’

Retired Met Detective Chief Superintendent Hamish Campbell said in 2021 that he believes Mr Williams was involved in sexual activity before his death.

In an interview with the Sunday Times, Mr Campbell said the death was different from the hits on Russian defectors Alexander Litvinenko in London in 2006, and Sergei Skripal in Salisbury in 2018.

‘What would have been achieved by killing a junior analyst?’ Campbell asked.

‘He was a phone analyst, an expert in terms of mobile phones and the transference of data. What would the Russians or any other state have achieved by killing him?’