A man who escaped from police custody after having been taken to Altnagelvin Hospital in Londonderry remains at large.
He is not believed to pose a risk to public.
The 40-year-old was one of three men arrested in Londonderry on suspicion of involvement in burglaries and other criminal acts in County Donegal.
He had been taken to the hospital on Tuesday afternoon after saying he was unwell.
It is understood that the police helicopter was in Coleraine yesterday as part of the search.