A new search for the remains of a teenager kidnapped and murdered by the IRA nearly 40 years ago has been called off.
Relatives of Columba McVeigh, 19, from Dungannon, Co Tyrone, who is believed to have been buried in bogland near the Irish border, said they are devastated.
His brother, Oliver, said: "Why do they continue to torture a family like this?"
The Independent Commission for the Location of Victims' Remains, which was set up by the British and Irish Governments a year after the signing of the 1998 Good Friday peace agreement, confirmed that the search at Bragan Bog, near Tydavnet, Co Monaghan, had stopped.
It was the sixth time a search had been carried out for the remains of Mr McVeigh, who vanished in November 1975.
The IRA claimed he was an informer - an allegation vehemently denied by his family, especially his mother, Vera, who died in May 2007, aged 82.
He wrote to her in September 1975, a month after attending the funeral in Dublin of then Irish president Eamon de Valera in which he described people weeping on the streets of the city.
He wrote: "It was a sight to be seen to be believed."
He signed off the letter: "We'll I'll say bye for now. God bless and take care. From your big son Columba."
The remains of six other victims, including Captain Robert Nairac, a British soldier kidnapped by the IRA in 1977, have still to be found.
Oliver McVeigh said: "There are people out there who have the information and they haven't come forward and I can't understand why. They have nothing to gain by keeping their secret and nothing to lose by telling the Commission what they know. They know that the information is confidential.
"Why do they continue to torture a family like this?"
Columba's sister, Dympna, said: "Our mother went to her grave unable to tend the grave of her son.
"If the people who know where Columba is buried could have seen what that did to my mother, if they could imagine their own mother in that position, they could not stay silent if they had any human feelings at all.
"I would like to look them in the eye and ask them 'Do you know what you have done?' Let us bring Columba home and end this torment."
Sandra Peake, chief executive of the Wave Trauma Centre which supports the families of the Disappeared, said the hearts of all the families of the Disappeared would go out to the McVeigh family.
She added: "It's a cruel irony that, just as Richard Haass is looking at ways of dealing with the past, a family is forced to endure more pain even though there is a process through the Commission already in place to deal with this terrible legacy of the Troubles."