HISTORIC letters which could be integral to attempts to prove the infamous Dr Crippen was innocent of murdering his wife went on display this week at the West's "black museum".

Crippen was hanged for the crime in 1910, but DNA evidence was produced in the USA a year ago that the headless body found in Crippen's cellar was not that of his wife.

Now, Andy Jones, of Crime Through Time at Littledean, in the Forest of Dean, Gloucestershire, tells me he has already had collectors bidding for the letters – as well as a distant relative of Crippen, one J Patrick Crippen of Michigan, USA.

But Andy's not selling them – and he's not saying how much he paid for the two letters either.

In August of last year, I put the then owner of the letters, Mrs Frances Johnson, 76, of Westward Ho!, Devon, in touch with Andy after she told me she was thinking of offering them for auction.

In 1943, ex-chief inspector Walter Dew, the CID man who investigated Crippen and arrested him when he fled to Canada with his lover Ethel LeNeve, received a letter implying that Ethel was the poisoner, and Dew sent a handwritten reply.

"It's a very rare letter because it's the first time Dew commented on the Crippen case," said Andy. "In British criminal history terms, it is a unique find and is a highly prized acquisition being sought by collectors all around the world."

Amazingly, Mrs Johnson found the letters tucked inside a copy of Dew's 1938 memoir, I Caught Crippen, which she bought at a second-hand bookshop in Cornwall.

Colin Bennett of Lydford, Devon, wrote to Dew suggesting that, while Crippen dismembered his wife's body (the head was never found), and buried the remains in the cellar of their home in London's Camden Town, he did not kill her.

Dew's reply was curt: "I am not prepared to enter in to any discussion on this subject, other than to say my conscience is quite at rest as (to) the result of the case."

But DNA tests carried out by Dr David Foran, a forensic biologist at Michigan State University, confirmed that the body in the cellar was not that of Crippen's wife Cora who, as a music hall singer, was also known as Belle Elmore. J Patrick Crippen had asked the British Government for a pardon for Crippen, said Andy, who added: "He is also thinking seriously about asking for the removal of Crippen's remains from an unmarked grave at Pentonville Prison to be buried in the family plot in his (J Patrick's) home town."

Dew had befriended Crippen while he was in custody, said Andy, and many criminologists and collectors believed Dew knew that Crippen didn't murder his wife.

Dew resigned shortly before Crippen was hanged and, a few days before his execution, Crippen wrote – prophetically, it now seems – to Ethel: "Face to face with God, I believe that facts will be forthcoming to prove my innocence."

The letter from Dew added further fuel to the debate, added Andy, he said: "Not only over whether he was innocent but also over the whereabouts of his wife, and who it was that was murdered and buried in the basement, and by whom.

"If that body wasn't Cora's, and she was still alive, she must have known her husband was innocent and was about to be hanged, yet didn't come forward and save his life. Bizarre to say the least!" Mrs Johnson said she and Andy had come to an "amicable arrangement" over the letters. "Thank you for being the reason I went to the museum," she told me.

Crime Through Time, a true-crime and "murderabilia" collection housed in the former Littledean Jail, has a number of other Crippen exhibits, including letters relating to his medical practice, and photographs of him visiting Symonds Yat West, near Ross-on-Wye.

The museum closes at the end of October and reopens at Easter.

Visit the website at www.littledeanjail.com