In May last year, a coroner concluded that Gareth Williams, who was working for Britain’s external intelligence service MI6 when he was found dead at his home in August 2010, was probably killed unlawfully by another person.

His spy background and the fact that expensive, unworn women’s clothes were found at his flat provoked a wide range of “weird and wonderful” theories, London Police Deputy Assistant Commissioner Martin Hewitt said, but further investigations now suggested it was more likely he had not been murdered.

“Most probably, it was an accident,” Hewitt told reporters. “I’m convinced that Gareth’s death was in no way linked to his work.”

Williams, 31, worked as a code breaker at the Government Communications Headquarters but was on a three-year secondment to MI6, which deals with foreign espionage matters.

The remains of the maths prodigy were found curled up inside a zipped and padlocked red hold-all at the London flat – an intelligence service “safe house” – close to MI6’s headquarters.

His body was badly decomposed after remaining in the bag in the August heat for a full week until he was discovered. Tests found no traces of alcohol, drugs or poison in his body. Detectives found no palm prints on the side of the bath nor any traces of his DNA on the padlock. Instead, they found make-up, a long-haired wig and unworn women’s clothes and shoes worth around 20,000 pounds ($31,900).

They also found images of transvestites, a picture of Williams wearing only boots, and evidence of visits to sexual bondage websites on his computer.

“This is a case where there’s been enormous theorising an speculating…and weird and wonderful stories,” Hewitt said.

Hewitt admitted the original police investigation had been flawed and after the inquest they pursued new lines of inquiry.

But detectives found no evidence anyone had been in the flat when he died. Hewitt rejected suggestions the flat could have undergone a “forensic clean” to remove traces of any killers.

He ruled out any suggestion that Williams interest in women’s clothing or his work as a spy had played a part, and said they did not believe he had meant to take his own life.

Despite the fact that there had always been doubt that someone could have locked themselves in a bag – a number of experts tried and failed – Hewitt said they now believed this was what Williams had done.

“It’s theoretically possible for someone to do that. It is a more probable conclusion that there was no other person present,” said Hewitt, who agreed Williams’s interest in escapology might have been a factor.

He could not categorically rule out anyone else being involved and said any new evidence would be followed up.

In a statement, Williams’s family said they still believed the coroner’s conclusions more accurately reflected what had happened, and repeated their anger that MI6 had failed to report Williams missing for days after he did not show up at work.

Hewitt denied suggestions Britain’s spies had simply staged an elaborate cover-up.

“I do not believe I have had the wool pulled over my eyes.” DM

Photo: A combination of still photographs taken from video shows a man trying to lock himself in a holdall in this undated image received from the Metropolitan Police in London on April 27, 2012. The video was shown to the Inquest into the death of MI6 officer Gareth Williams, who was found dead in his flat locked in a hold-all.(Reuters)