A new book has claimed to have solved arguably the biggest unsolved murder case in history. Based on DNA evidence, Russell Edwards, self-proclaimed "armchair detective" and author of the new book "Naming Jack the Ripper," has identified a 23-year Polish immigrant as the murderer behind the myth that has become Jack the Ripper.

Edwards, who said he was partly inspired to take up the search after watching the 2001 film "From Hell," starring Johnny Depp, joined forces with Jari Louhelainen, a Finnish geneticist and lecturer at Liverpool John Moores University, England.

For over three and a half years, Louhelainen used pioneering techniques to analyze DNA from a blood-stained shawl belonging to one of the Ripper's earlier victims. Catherine Eddowes was found in London's Mitre Square on the morning of September 30, 1888 with her throat slit and abdomen cut open and with her left kidney and part of her womb removed.

Grisly gift

Bought at an auction in Bury St Edmunds, England, in 2007 the shawl was also found to have traces of semen, thought to belong to Eddowes' killer.

The shawl which, bizarrely, had been taken from the scene by acting Sergeant Amos Simpson, to give to his wife, who was understandably horrified, had been stored away and passed down through the generations, unwashed.

Having tracked down living descendants of both Eddowes and Kosminki, Edwards and Louhelainen were able to find matches betwen the DNA sequences of the distant realatives and the DNA samples recovered from the shawl.

"I've got the only piece of forensic evidence in the whole history of the case," Edwards wrote in the British Mail on Sunday newspaper. "I've spent 14 years working on it, and we have definitively solved the mystery of who Jack the Ripper was."

"Only non-believers that want to perpetuate the myth will doubt. This is it now - we have unmasked him," said the 48-year-old. "When we discovered the truth it was the most amazing feeling of my entire life."

Suspect

Edwards said Kosminski, was "definitely, categorically and absolutely" the killer behind the gruesome murders of five women between August 31 and November 9, 1888.

Kosminski, who had fled persecution in Poland, then under Russian control, arrived in England with his family in 1881 where he lived in Mile End, east London.

Police had in fact identified Kosminski as a suspect at the time, Edwards said, but they never had enough evidence to bring him to trial.

At the time of the Ripper murders, anti-Semitic protests erupted over a disputed message written on a wall in Goulston Street, believed to be from the killer identifying himself as Jewish. The message, however, was washed away amid fears of further anti-Semitic riots, leaving its authenticity and true meaning to be disputed ever since.

Kosminski died in a lunatic asylum in 1899 after contracting gangrene in his leg.