The identity of a man whose body was washed up in Seaham in 2006 remains a mystery
There are currently 1,000 unidentified bodies on police files in the UK, some dating back 50 years. Last year, a website featuring facial reconstructions and, in rare cases photos of the dead person's face, was launched in the hope of solving them. So far, none have been solved.
A young man found hanged in secluded woods and a mystery body washed up on a beach are just two unsolved cases which have baffled Teesside detectives for years.
What little is known about them is detailed on the UK Missing Persons Bureau website along with seven other mystery bodies found in the North East and Cumbria.
Det Insp Paul Tait, head of Cleveland Police's force intelligence bureau, is aware the website is a long shot.
"It's clutching at straws a bit, but someone might be looking on the website and some little detail might jog a memory.
"But I don't like having unsolved cases because there is always that possibility that foul play has been involved, and I want to rule that out," he added.
The website was launched in November 2012 to ID mainly unidentified bodies
Sometimes all scientist have to work with is a body part or bones.
In 1999, a trawler found a skull, 15 miles off the coast of Blyth, Northumberland.
Scientists determined it was a man, narrowed the age to between 30 and 40 years, and that he had been dead for more than six months, but less than 10 years.
Yet, despite being on the missing person's website for seven months, there have been no new leads.
DNA samples are taken and stored and, if someone believes they may be related to a missing person, their DNA can be tested and compared.
"Within reason if it was a credible line of enquiry - all unidentified bodies found will have a forensic examination conducted," Mr Tait explained.
Foul play
Cleveland Police is informed of 3,000 deaths every year - only a fraction are foul play.
The oldest case is the body washed up in 1970 at Redcar.
It was so decomposed that the sex could not even be determined and the age was recorded as anything between 21 and 100.
The only real clue was a black boot, very well preserved but unfortunately not very distinctive.
He said: "The problem with remains from the water is that they can have been there a long time, and have travelled some distance.
"The chances are that a person washed up here could be from abroad," he explained.
The boot was well preserved, but unfortunately not very distinctive
Another case is that of a young man found hanged near the A178 Graythorpe to Seal Sands Road in Hartlepool in 1981.
Even thought he had only been there a day, was fully clothed and had 'Sayer' written on the inside of his trainers, the case is still open 30 years on.
Police estimate he was aged between 20 and 30 but, although no foul play is suspected, it cannot be ruled out while the case is unsolved.
Badly decomposed
Another inquiry to remain open is that of a body washed up on the banks of the River Wear in 1992.
It was the badly decomposed lower half of a man aged 55 to 65, but with some small, unique features such as a gold, horseshoe earring.
He was also carrying a box of Altoids seriously strong peppermints made in York.
Once the police have finished, it is up to the local authority to bury and cremate any remains.
Certain cases do not feature on the site including babies and partial remains, such as single bones, as publicity would be pointless.
A spokesman for the Missing Person's Bureau said: "The aim of the site is to bring closure to the families and friends of the people featured.
"With new unidentified person cases we rely on modern forensic techniques but on older cases we believe that publicity is the best chance of getting images recognised."
By Julie Cush
BBC News