Harvey Richardson, 77, left nine sides of A5 paper detailing the strangulation of 19-year-old Lorraine Jacob in September 1970.

The teenager's body was found by binmen in the city centre.

Her death remained without any real clues until decorators found a gun, a letter, clothing and press cuttings about the killing in Richardson's home in Aspull, near Wigan.

On Wednesday, Merseyside Police issued a photograph of languages student Richardson when he was 36, four years before the killing.

The man leading the murder inquiry, Detective Superintendent Ian Kemble, said his team were working to corroborate the confession which was "detailed" and being studied by forensics and handwriting experts.

Saying that it was unknown how many people could be responsible for the mother-of-two's death, he said of the letter: "The confession isn't dated, it's not signed, so how do we know he wrote it? Well, we don't know that until we have expert evidence.

"It would appear to be quite old with yellow staining.
"I don't think it is something that has been written in the last five or six years."