A workman excavating sand from a river bank has unearthed skeletal remains believed to be a man missing since fleeing police custody.
The decomposed body, believed to be 21-year-old David Colhoun from Lifford, Co Donegal, was dug up by a digger driver working at the River Foyle just outside the town.
Gardai said the remains were found at 9am about three miles north of Lifford at a spot called Islandmore.
Mr Colhoun's family, including his father Joseph, were immediately notified and spent several hours at the scene as further searches were carried out on the river banks.
Superintendent Vincent O'Brien said it would be weeks rather than days before the remains are formally identified.
He said: "It will be down to DNA to establish if the body is male or female or if it is the body of David Colhoun. Naturally the family would believe that there's nothing to suggest otherwise but to be sure we will have to conduct DNA testing."
Supt O'Brien, who was at the scene, said it was too early to speculate on the cause of death. Further searches along the river bank have been carried out.
Mr Colhoun went missing last May after escaping custody from the Police Service of Northern Ireland in Strabane.
Some of his clothing was found in November last year and it was feared he had attempted to swim across the River Foyle to his home in Co Donegal.
A post-mortem examination is to be carried out later and the Coroner's office in Donegal will be notified.