The search for in a Co Monaghan bog for the remains of Columba McVeigh has concluded for the evening.
Mr McVeigh was abducted and killed by the IRA in 1975, when he was aged 17.
Two previous searches in the area in recent years were unsuccessful.
The latest search was prompted by information passed on to the Commission for the Location of Victims' Remains from the IRA through an intermediary.
It will resume in the morning.
Last week, Mr McVeigh's mother Vera, said she wanted to bury her son's remains before she herself passed on.
She said she hopes that God will guide the Gardaí to her son's resting place.
Today's operation comes ten days after what appear to be the remains of another one of the disappeared, Jean McConville, were found in Co Louth.
