A RETIRED police officer turned “armchair detective” believes he has uncovered new evidence linking the Yorkshire Ripper to 23 unsolved murders.

Chris Clark, from Crook, County Durham, has now written a book on his research into unsolved murders carried out in the 1970s.

The 69-year-old first started delving into the cases after he discovered his wife Jeanne had almost been abducted as a child.

Through his research he now believes she had a near miss with notorious child killer Robert Black, who kidnapped and murdered four girls in the 1980s.

But after coming to a dead end, the former police officer, who worked for Norfolk Constabulary, turned his attention to unsolved murders.

“I started looking at it but I came to a stumbling block. But what I found was all these unsolved murders of women. I started looking at it and I’ve spent two years delving into it.”

According to Mr Clark, Peter Sutcliffe – convicted of murdering 13 women and attempting to kill seven more – could have been responsible for up to 23 more, which have never been solved.

His research, through online archives and with access to some of pathology reports, has led him to write Yorkshire Ripper: The Secret Murders with investigative journalist Tim Tate and published by John Blake.

They allege that truck driver Sutcliffe, who lived in Bradford committed his crimes all over the country, with cases in the Midlands, London, Essex and Bristol, and have identified cases which they argue bear all the hallmarks of a Ripper murder.

Among those they say could have been Sutcliffe’s victims are Gloria Booth, who was tortured and mutilated at a London garage, 14-year-old Judith Roberts who was battered to death in Staffordshire and Wendy Sewell, beaten to death in a churchyard in Bakewell, Derbyshire.

“I would say I’m about 95 per cent sure about these cases. There’s one which could be or couldn’t be and I didn’t have enough research to prove it. In all of these cases there have never been any suspects.

“Some of the families are very supportive and some don’t want the stigma of the Yorkshire Ripper attached. He was painted as someone who only attacked prostitutes but that wasn’t actually true. Of these cases only two are prostitutes and the rest were nurses, school teachers, students and office workers.”