Brendan Megraw
Human remains have been found in the search for Brendan Megraw.
The remains were found in County Meath, in a ditch at Oristown bog near Kells.
A forensic team had been searching for the body of Mr Megraw after he disappeared almost 40 years ago.
The 23-year-old was abducted in Twinbrook in 1978. He was taken away and murdered by the IRA who claimed that he was an undercover British agent.
The Independent Commission for the Location of Victims' Remains confirmed that the remains of a body have been recovered.
There have been three previous searches for the body of Mr Megraw before now, with the latest commencing in August of this year. The most recent search of five acres of bogland which have not previously been examined came after the ICLVR received new information.
A spokesperson for the organisation said: "The recovery of the body is now underway and the State Pathologist will begin the process of post-mortem and of formal identification."
The ICLVR was set up as a joint initiative between the Irish and British governments so that former paramilitaries could liaise with authorities in order to recover the bodies of the 16 Disappeared.
The brother of Brendan Megraw, Kieran Megraw, spoke of his family's mixed emotions, saying: "We still have to get confirmation that it is actually Brendan, but it's within the area that they were going to start searching, so you have to be hopeful.
"It's a joy that a body has been found, but there's also a sense of sadness too."
The recovery of the body is now under way.
It is understood the excavations proper had not begun and clearance and preparation works were taking place when the discovery was made.
Forensic archaeologists surveyed the remote bogland one month ago and have spent the last few weeks analysing radar surveys, searching for anomalies in the ground.
Separate searches have also taken place on bogland a few miles from the Oristown site, near Wilkinstown, for Kevin McKee and Seamus Wright, both of whom were taken by the IRA in October 1972.
It is also suspected Joseph Lynskey, a former Cistercian monk taken from the Beechmount area of west Belfast in the summer of 1972, was also buried somewhere in the region.
Investigators believe one person living locally may hold vital clues to several families' decades-long quest to find the bodies of loved ones.
The IRA claimed Mr Megraw had confessed to being a British provocateur and Military Reaction Force undercover agent in 1978.
The ICLVR was established in 1999 after the Good Friday peace agreement and is acknowledged as a world leader in the search and recovery of human remains from bogland.
The remains of 10 of the Disappeared have been recovered.
The Megraw family were notified about the discovery at about 10am.
Kieran, one of Brendan's brothers, said he hoped the discovery would end feelings of helplessness.
"For our own family it was not until 1999 that we knew Brendan was dead and buried in Oristown. There will always be questions, but if this is Brendan and we get him home, that is the target.
"The target was to get Brendan's body back. If he was killed at the spot in Oristown he was all alone, and you think he would have thought he would never be back home - that's the thought most people would not want to happen to them, being alone.
"There was always a massive frustration when you felt that he was there and you couldn't find him and couldn't bring him home - that's now gone, we hope."
When contacted by forensic investigators this morning family members were asked what Mr Megraw might have been wearing at the time he disappeared, with one brother, Sean, suggesting it could have been a duffel coat and jeans.
Kieran Megraw said thoughts should also be with other families of the Disappeared whose quests continue to find loved ones abducted by the IRA.
"We are over the moon but surprised that it has come so quick after all this time," he said.
"I didn't really expect to get the call. And it is looking like it really is Brendan, obviously there will be DNA tests and so on.
"It is quite a shock for the family. Sometimes you maybe ask yourself twice, has it really come about, but there's joy and relief that it looks like it is his body."
Sinn Fein leader Gerry Adams welcomed the discovery.
"I hope the identity of the remains can be quickly verified and that this discovery will bring some closure to the family and loved ones of Brendan Megraw," he said.
Mr Adams appealed for anyone with information on the Disappeared to contact the commission and insisted they would not face prosecution.