A specially trained dog will be used today to help in the effort to find one of the Disappeared.
The IRA kidnapped, killed and secretly buried former monk Joe Lynskey, who was last seen in west Belfast in August 1972.
Preparatory work began at an area of bogland in County Meath last month after fresh information came to light.
The scene of the work is close to the site where another of the Disappeared, Brendan Megraw, was found buried in October.
Just last month, the funeral took place of Brendan Megraw, one of the so called Disappeared whose body was found in Oristown bog in Co Meath last month.
He was 23 years old when he was abducted from Twinbrook in Belfast and killed by the IRA in 1978.
His wife, who was drugged during the kidnapping, was pregnant at the time of his disappearance.
