A search for the remains of the first of Northern Ireland's Disappeared is getting under way in Co Meath.
A sniffer dog will be used in the initial survey for the remains of IRA man Joe Lynskey in Coghalstown.
The former Cisterian monk was taken from west Belfast by the Provos in August 1972 after being quizzed by the security forces.
If the search proves successful, his remains will be the 11th of the Disappeared to be recovered by The Independent Commission for the Location of Victims' Remains (ICLVR) since its creation.
However, the ICLVR's lead investigator has warned that it could be several months before the family of Mr Lynskey will finally be assured that his remains can be laid to rest.
Geoff Knupfer said: "As with of all of the Disappeared, we are facing a huge task in this case going back over 40 years and dealing with a search area of around 15 acres in the first instance.
"We have to remember that it took four searches over nearly 15 years before we found Brendan Megraw.
"We are just at the beginning of the process for Joe Lynskey."
The former police inspector stressed that the search would uncover Mr Lynskey's remains if, as in the case of Brendan Megraw, whose remains were recovered last month, accurate information about the location was received.
The forensic investigator added that the search would take months rather than weeks and said: "We cannot over-emphasise the importance of information coming to the ICLVR.
"I can give the assurance of a cast-iron guarantee of complete anonymity to those who bring information to the commission."
Mr Lynskey was from the Beechmount area of west Belfast and his name was not officially added to the list of the Disappeared until 2010.
In the 2012 book The Disappeared, published by the Wave Trauma Centre, Mr Lynskey's niece Maria recalled the last time she saw her uncle at her aunt's house in the St James's area of the city.
She said: "He disappeared shortly after this. Speculation arose that Joe was lifted by the Army and questioned by the police in Castlereagh.
"Rumours began to circulate about his whereabouts but none of them turned out to be true."
She said that she felt "a bit of a fraud" after meeting other relatives of the Disappeared as she had not really known her uncle.
She added: "I remember him as a quiet timid man and he did exist. To me everyone's existence deserves to be acknowledged."