Media playback is unsupported on your device Media caption North Wales Police want to establish their identities to give families closure

Police are appealing for help to identify 17 people whose remains have been discovered dating back over 40 years in north Wales.

Their bodies were found between 1968 and 2011, mainly around the coast.

And although the separate cases are not being treated as crimes, North Wales Police want to establish their identities to give families closure.

Officers are hoping advances in science could help finally identify them and they also want people to come forward.

Det Con Don Kenyon, who is leading the investigation, said: "When somebody dies and a body is found, even if that death is under suspicious circumstances, the family is able to understand what's happened.

"In this case, the family haven't had chance to grieve because they don't know if their husband, father or son is dead or alive anywhere."

More than half the cases involve bodies found by the sea, including a man aged between 45-60 who was found dead at the base of cliffs near South Stack, Holyhead, Anglesey, on 15 September 1975, and a woman found in the sea off Barmouth, Gwynedd, on 28 June 1976.

CASE STUDIES: UNIDENTIFIED REMAINS

Image caption A rucksack similar to this was found with the body a man in the sea off Holyhead in May 1982

Woman found in the sea off Barmouth on 28 June 1978: She was wearing a "St Michael" (Marks and Spencer) swimsuit which may indicate she drowned. She had been in the water for some time.

Man aged between 45-60 found at the bottom of cliffs Hen Borth, South Stack, Holyhead, on 15 September 1975. He had been dead for about five days, and wearing a distinctive pendant of two boys back to back in a circle

A 20-something man who apparently took his own life at Llanfairfechan railway station, Conwy county, on 20 September 2002. He was 5ft 6in (1.67m), medium build, and he weighed about 10st 10lb (68kg). Collar length brown hair. Small hands. Two upper front teeth were crowns. He was wearing black jeans, black and grey polo shirt and black underwear. Probably smoked Richmond cigarettes

Man aged between 25-30 whose body was found in sea off Holyhead on 30 May 1982. He was dressed in outdoor-type clothing with a rucksack (pictured). He could have been in the water for a month

A man aged 50-60 (pictured above in a police e-fit) who died around 22 May 2011. He had been camping in Capel Curig, Conwy county. He was thin, with short brown hair and a beard. He had the skin condition vitiligo which causes patches of white skin. Although he was thin, he wore size large clothes. Police say this could mean his clothes were from charity

Source: Operation Orchid / North Wales Police

Det Sgt Peter Jarvis said: "With the passage of time and the development of forensic examination and the scientific support that we've now got in place, we're able to look at other avenues.

"It's that new technology and new scientific method that we're now trying to utilise to bring closure to these cases for the families."

The police call this trawl through the files Operation Orchid.

They admit that many of the bodies found on the coast may never be identified, particularly if they had been washed there from abroad.

But DC Kenyon added: "People may not have had direct memories, but there might be a story of an aunt or an uncle who's gone missing in years gone by. That's what we'd like to hear from people in Wales and further afield."

Contact DC Don Kenyon at North Wales Police by calling 101 or email: don.kenyon@nthwales.pnn.police.uk