The search has resumed for the remains of disappeared victim Columba McVeigh on bogland in Co Monaghan.
A previous search for his body ended in May but investigators with the Independent Commission for the Location of Victims' Remains said they were returning to the same site due to "a refinement of information".
The search operation at Bragan Bog is expected to last for approximately three months.
Mr McVeigh was 19 when he was abducted from his home in Donaghmore, Co Tyrone, and murdered by the IRA in October 1975, who later accused him of acting as a spy for the British forces.
So far, nine bodies have been found to date out of the total of 16 people on the commission's list of the disappeared.