THE murders were monstrous, the tale chilling, the case never solved; but a Worcester man could have the answer to one of the biggest questions in criminal history - who was Jack the Ripper?

'Jack' was one of the most horrific murderers ever to walk these shores, butchering at least five women within the space of a few months in 1888, in Whitechapel, London, before the killings suddenly stopped.

Chief Inspector Donald Sutherland Swanson was the man in charge of tracking down the serial killer, and although there was never any shortage of suspects he wasn't able to bring any of them to justice for a lack of damning evidence.

But that is not to say he didn't have a clue who it was.

And the clue lies in a book that has been passed down from generation to generation in the Swanson family only to end up in the hands of Nevill Swanson, of Barbourne Terrace, Worcester, who is the great-grandson of the 19th Century sleuth.

The book, entitled The Lighter Side Of My Official Life, was presented to his great-grandfather by one of his former bosses, ex-assistant police commissioner Sir Robert Anderson.

Within the book are passages written by Sir Robert about the Ripper case and, in his retirement, Donald Swanson pencilled in his thoughts next to those particular paragraphs as to who he thought the killer was - namely, one Aaron Kosminski, a Ukrainian barber who moved to London in 1882 and had a history of mental illness.

The name is not a new one in the long list of suspects, but the carefully-written notes in pencil give a good indication of the thoughts and beliefs of the man who was heavily involved in the case.

"My great-grandfather was involved in the investigation every minute of every day - he saw the lot," declared Mr Swanson, whose first name, Nevill, derives from the wife of the chief inspector - Julia Ann Nevill.

"He was a great detective and solved the case, he just wasn't able to get the guy convicted because the one witness they had wouldn't testify."

Donald Swanson's notes read: "...because the suspect was also a Jew, and also because his evidence would convict the suspect, the witness would be the means of the murderer being hanged which he did not wish that to be left on his mind."

But even though this appears to be concrete evidence in revealing the identity of 'Jack', many Ripper-ologists dispute the claim that Kosminski was the real killer.

"I don't think it'll ever be solved properly," said Mr Swanson.

"There's a whole industry dedicated to it so it's in their interest that it isn't."

The 68-year-old described his great-grandfather, who was a Greek and Latin scholar born in Thurso, Scotland, in 1848 before moving down to London to join the force in 1868, as being a "very quiet and modest man".

Mr Swanson added: "Maybe that's why he never wrote a book of his own - because he thought that was police business and not in the interest of the public."

But the book in which he wrote was discovered by Nevill's father in 1980, when he inherited the belongings of Donald Swanson's unmarried daughter.

"He had a flick through the book and realised straight away it was very significant," he said.

"He tried to bring it to the attention of the Press and actually received a cheque for £1,000 from the News of The World, but they never ran the story which angered my father a bit."

However, the story was finally bought to the public's attention in 1987 when the Daily Telegraph published details of the find.

The book was eventually given to Mr Swanson by his father before he died in 2001, but was recently presented to Scotland Yard, by him, on open-ended loan to mark the re-opening of the force's Crime Museum.

"I was told it was going to be a low key affair," he said "but after the presentation I was asked to meet the Press.

"I was just expecting a couple of reporters but there was a whole room full!"

Proof, then, that even though the case is more than 100 years old, people of all ages and from all walks of life are still enthralled by the grisly legend of Jack the Ripper.

Parting company with the book has been in the pipeline for a few months, but Mr Swanson said he was not too sad to no longer have the work to hand.

"We still own the copyright and we can get it back anytime, but I wanted it to be in an appropriate place.

"I wanted it to be safe and secure."

He can rest quite assured it will be safe and secure at Scotland Yard.