The Sligo-based Rescue 118 coastguard helicopter was tasked from Sligo to Derry last night to aid a missing person search.
The Northern Ireland Fire and Rescue Service had specialist water search teams at the scene close to Craigavon Bridge, which was also attended by the PSNI and Foyle Search and Rescue.
The search began at around 9pm and the Rescue 118 crew left the scene just before 11pm.
