A search is to get under way in Armagh for the remains of Seamus Maguire, one of the so-called Disappeared.
The 29-year-old, from Aghagallon, near Lurgan, was murdered and secretly buried by republican paramilitaries in 1976.
The search at Derryclone will be the first for the remains of Mr Maguire, who was categorised as one of the Disappeared in 2022 on foot of information received by the Police Service of Northern Ireland (PSNI).
His name was added to those being searched for by the Independent Commission for the Location of Victims' Remains (ICLVR) in 2022.
ICLVR lead investigator Eamonn Henry said the search area is around two acres in size and on farmland.
He said that he was not going to put a specific timeframe on the search, and as with all such operations, teams will be there until they find what they are looking for or are satisfied that Mr Maguire's remains are not there.
In a statement, the Maguire family said Seamus was their much loved eldest brother, missing now for over 50 years.
They said they hoped the search would be successful, so that he could be buried in St Patrick's graveyard in Aghagallon with his parents, May and Patrick.
"Our mum looked for Seamus right up until the day that she died," they said.
"We appeal for privacy at this time."
They also thanked the ICLVR and all those involved in the search process.
Mr Henry also said it had been initially thought that Mr Maguire disappeared sometime around 1973-1974 but it was also subsequently suggested that after spending time in Manchester, he may have returned to Northern Ireland and was then killed and secretly buried in the Aghagallon/Derryclone area in 1976.
The commission said it is believed that republican paramilitaries were involved, although it is not clear which wing of the IRA was responsible.
Mr Henry also said that just because a search had started that did not mean the ICLVR had all the information it needed and appealed for anyone with information on the case to come forward, adding that it will be treated in the strictest of confidence.
He said the sole purpose is to return the remains of a loved one to their family for a Christian burial.
Mr Maguire is one of four people whose remains are still being searched for by ICLVR.
The other three are Columba McVeigh, Joe Lynskey and Robert Nairac.
The latest search is also the first time since the discovery of the remains Peter Wilson at Cushendall in 2010, that a search for one of the Disappeared is taking place in Northern Ireland.
Northern Ireland Secretary Hilary Benn said: "My thoughts are first and foremost with the Maguire family, who have endured so many years of anguish since the abduction and disappearance of Seamus.
"I am deeply grateful to the commission for their unceasing efforts to find the Disappeared and for their painstaking efforts to help ease these families’ long-suffering.
"As well as the Maguire family, the families of Columba McVeigh, Joseph Lynskey and Robert Nairac still await the return of their loved ones’ remains.
"I urge anyone with information – no matter how insignificant they think it may be - to come forward and speak to the commission.
"All information will be treated in the strictest confidence."
Additional reporting PA