Experts say scientific advances could provide the key to solving the 41-year mystery of an unidentified body found in the River Aire in Leeds.
The man was pulled from the water near Methley in 1974 – an inscribed spectacles case and a bottle opener the only potential clues to his identity.
A police investigation at the time concluded that his death was not suspicious, but failed to determine who he was.
Question marks continue to hang over the case more than four decades later.
It is one of 15 unidentified body cases from across Yorkshire which feature on the website of the Missing Person Bureau – the national unit that helps police forces try to solve such long-running mysteries.
Sherri McAra, tactical analyst at the bureau, said hope was never lost.
She said: “I believe that, with the advances we are seeing in forensic technology, and forces running cold case investigations, there is always hope that these cases can be solved.”
The Yorkshire Evening Post reported at the time that a man’s body had been found in the river at Methley on March 10, 1974.
He was white, aged 50 to 60, about 6ft tall and wearing a jacket and jumper as well as size 11 shoes.
The only items found on his person were a bottle opener and a spectacles case inscribed with the opticians Sydney Goldwyn.
The YEP report from the following day said he may have been in the water for up to three weeks and quoted a police spokesman saying: “We do not suspect foul play.”
Speaking today, Det Chief Insp Peter Craig, West Yorkshire Police’s lead officer for missing people, said the vast majority were found quickly. In longer-running cases DNA samples are obtained for comparison with any bodies that are recovered later.
He added: “Clearly DNA techniques were in their infancy when this body was recovered and similarly the computerised recording of files has developed enormously since then and enhanced our procedures immeasurably.
“However old the missing persons case, we continue to review them and make enquiries on a periodic basis. We fully appreciate that identifying recovered bodies, no matter how long ago they were found, provides vital closure for families and we never close our enquiries into these cases.
“It is to this end that this case is still featured on the UK Missing Persons Bureau website and it is still hoped that someone may come forward with information to help identify this person.”