DNA evidence has emerged linking infamous Victorian serial killer Jack the Ripper to a man who died in Leavesden mental hospital.

Leavesden asylum patient Aaron Kosminski had been the prime suspect in the shocking Whitechapel murders, which saw the gruesome mutilation of five prostitutes in the East End of London during the autumn of 1888.

But now an armchair detective on a seven-year quest to finally identify the killer says he can definitively prove hairdresser Kosminski, a Jewish immigrant from the Russian Empire, was Jack the Ripper.

Barnet man Russell Edwards, 48, purchased a shawl at an auction in Suffolk in 2007 rumoured to have been taken from the body of one of the Ripper's victims, 46-year-old prostitute Catherine Eddowes.

It was stained with blood in the distinctive spatter pattern left from a slashed artery.

He subjected the shawl to DNA analysis and matched the blood to samples from the victim's descendants.

It was proof the shawl had been found on her body, but a forensics team also discovered semen stains on the garment.

Mr Edwards tells in his new book Naming Jack The Ripper how he managed to track down a descendant of Kosminski, who was 25 at the time of Eddowes' murder, and a 100 per cent DNA match was established - finally putting an end to the mystery that has captivated the nation for more than 125 years.

But in the 19th century police did not have the evidence to charge Kosminski.

They had a witness who identified Kosminski as a man seen loitering near the scene of one of the murders and his suspicious behaviour when questioned.

It was enough for the Victorian detectives to zone in on Kosminski as their number one suspect, but not enough for the courts.

All they could do was keep a close watch on him.

In 1890 Kosminski suffered a schizophrenic break, threatening his own sister with a knife.

He was committed to Colney Hatch lunatic asylum with his hands tied behind his back to stop him abusing himself.

Then in 1894 he was moved to Leavesden mental hospital, in Abbots Langley, where he lived until his death aged around 53 in 1919.

Chairman of the Leavesden Hospital Historical Association, Martin Brooks, has always been convinced Kosminski committed the gruesome murders.

Mr Brooks said: "I've always said it was him. The medical examination, forensics and psychological evidence all points to him being a serial killer.

"Eddowes was his last victim, and the most horrible of the murders."

Mr Brooks said it was very likely that after Kosminski died in Leavesden hospital, he was buried in the north cemetery in Leavesden Country Park.