The search on bogland near Emyvale, Co Monaghan, for the remains of IRA victim Columba McVeigh may end by Friday, the Garda say.
A Garda spokesman said a team was still working from 8 a.m. each morning until late at night in a bid to find the young man's remains. Mr McVeigh (17) was abducted and murdered by the IRA in 1975.
The search for his body resumed last week after the Commission for the Location of Victims' Remains received new information from the IRA about the spot where he may have been buried.
An area at Bragan, Co Monaghan, was searched for Mr McVeigh's remains in the summer of 1999. The current search is taking place at an 80-by-40 metre square section of bogland beside the sites searched at that time.
Progress has been slow due to the nature of the terrain and also due to recent rain which has made the ground harder to dig.
Members of Mr McVeigh's family visited the site when the search started early last week.
A Garda spokesman told ireland.comthe Garda did not want to place a "full stop" on the search but there was a limit to what could be done on the site. This would probably mean pulling out of the site by Friday if nothing was found, he said.
The spokesman said there were a couple of smaller areas of ground that would probably be searched before the team pulled out.
The new search for Mr McVeigh's body got under way 10 days after what are thought to be the remains of another of Northern Ireland's "Disappeared" people, Ms Jean McConville, were found on Shelling Hill beach near Dundalk.