The family of one of the Disappeared, Seamus Ruddy, said they are being misled in the search for his body.
Mr Ruddy, 32, from Newry, was working as a teacher in Paris when he went missing in 1985. It is believed he was killed by members of the INLA.
The family were told his remains were in a forest in Normandy, but they found nothing.
His sister, Anne Morgan, said the person who gave them the information had "led them up the garden path".
Representatives from the Independent Commission for the Location of Victims Remains went to Normandy last week accompanied by forensics experts from the UK and the Republic of Ireland.
It was the latest in a series of visits to the site by the commission, which was set up to recover the bodies of those murdered and secretly buried, mainly by the IRA, in the 1970s and 1980s.
Ms Morgan said the team had been investigating a site next to one they searched eight years ago.
"The information which was given was from the same individual who had given information for the 2000 search," she said.
"So he has literally led our family up the garden path concerning the recovery of Seamus's body.
"He has wasted forensic experts' time, their energy, money and he has wasted 23 years of our lives waiting for this moment."
The commission has asked anyone with information to contact them.
"Work concluded at the weekend and unfortunately, no remains were found," a spokesperson said.
"The Ruddy family has been kept fully informed during all stages of the search.
"The Commission has no further information on where Seamus Ruddy may be buried, but the case remains open."