Rescue services last night discovered a mass of floating wreckage off the west coast.
The alarm was raised at Clyde coastguard station in Scotland at 1.10 p.m. when it received a distress call from a position indicating radio beacon.
The beacon was a 121 decibel 5 type, often found on small aircraft or yachts. An Irish Sea Fisheries patrol aircraft was sent to the location and discovered a floating mass of wreckage 220 miles west of Blacksod Head on the Mayo coast.
A passing tanker, the Karela Spirit, was sent to the area to investigate. An RAF Nimrod search- and-rescue aircraft also flew out to search for possible survivors. Malin Head coast guard in Donegal communicated between the tanker and Clyde coast guard which co-ordinated the search.
The tanker reached the area at about 7 p.m. last night and managed to haul some of the wreckage aboard to try and identify it. According to Malin Head coast guard, the wreckage consisted of pieces of yellow, brown and blue fibreglass and wood.
Seamen on the tanker were unable to identify the wreckage. "There's no way of saying whether it's an aircraft or a vessel," said a spokesman from Clyde coastguard.
"Both the tanker and the Nimrod are conducting a search of the area but haven't found any people," he said. He said it was possible that a small aircraft could have flown out that far into the Atlantic.
The Karela Spirit searched the area until darkness fell before continuing on to its destination at Scapa Flow in the Orkney Islands, Scotland. The RAF Nimrod was expected to continue searching using radar equipment last night.
Malin Head coast guard confirmed it received no maydays at the time of the beacon distress signal. It said the beacon would have started transmitting when it hit the water.
Efforts to identify the wreckage will continue.