A personal friend of Queen Victoria has joined the long list of suspects accused of being serial killer Jack the Ripper.
The Jack the Ripper murders still inspire countless films and books
A new book by Tony Williams, from Swansea, claims that his ancestor Dr Sir John Williams was the murderer.
Sir John was a doctor to the royals and also a founder of the National Library of Wales in Aberystwyth.
The national library dismissed the allegations and said it was proud of what its first president had achieved.
Mr Williams said he unearthed evidence linking the unsolved crime to Sir John while carrying out research into his life. And he even claims to have found the knife used to butcher five prostitutes in London's Whitechapel district.
He claimed his research showed that Sir John, his grandmother's great-great uncle, knew all five of the Ripper's victims and had even treated them.
Between August and November 1888, Jack the Ripper terrorised the east end of London.
It is a criminal case where a year rarely goes by without a new development or conspiracy theory.
Mr Williams said he was convinced his relation, born at Blaenllynant, Gwynfe, Carmarthenshire, in 1840, was the killer.
He was given access to Sir John's personal effects at the library because of his family links which he says includes a large knife.
He added that he may have been driven to commit murder in the name of medical research, because his wife could not have children.
"I started researching Sir John because I was proud he was my relation," said Mr Williams.
"While I was researching, I read in his diaries and medical notes in the national library that he knew the Ripper's first victim Mary Anne Nicholls."
Mr Williams, who has published his findings in a new book called Uncle Jack, said Sir John had carried out an abortion on her in 1885.
"Other diaries and medical notes in London and Cardiff revealed that Sir John knew all five victims, had treated them all and had links to Whitechapel where the murders were committed." he added.
"I think he was a Jekyll and Hyde-type character who may have been driven to commit murder because his wife could not have children.
"He was also known to be working on a cure for his wife's problem."
He added: "I believe that knife, which still rests at the National Library
of Wales may contain clues to the Whitechapel murders.
"If that knife could be examined using modern DNA techniques maybe there
would be links to some of the victims."
JACK THE RIPPER SUSPECTS
Prince Albert Victor - grandson of Queen Victoria
Dr William Gull - Royal physician
Montague John Druitt - Barrister and teacher
Walter Sickert - Artist
Sir John was a personal friend of Queen Victoria and wrote to her two or three times a day on occasions, said Mr Williams.
He was also her daughter Princess Beatrice's gynaecologist.
Former Bedfordshire police detective Trevor Marriott - who has researched the crimes in the Whitechapel area of east London - said he had not heard of Sir John Williams before.
"If Mr Williams has proof and evidence of who Jack the Ripper was then that's good," he said.
"It's there to be tested and shot down if it's not right."
Mr Marriott, who has been interested in the Ripper murders since the 1960s, said he decided to re-investigate the crimes himself two years ago.
The National Library of Wales dismissed Mr Williams' research.
A spokesman said: "The library thinks there's no basis for it at all.
"We're very proud of the contribution Sir John Williams made in bringing the national library to Aberystwyth."