A hi-tech scanner has proved unsuccessful in the search for missing Lifford man David Colhoun.
It was the first time the equipment has been used in the Northwest.
The 22-year-old has not been seen since escaping from police custody after being arrested for minor offences in Strabane in May.
Hundreds of locals, Gardai, the PSNI, Foyle Search and Rescue, the Civil Defence and Searching for the Disappeared have all helped in the search over the past six months.
John Wolf, Chairman of Mallow Search and Rescue in County Cork, who brought the hi-tech device to help in the search, said finding anything was a long shot, but it was worth a try: