The helicopter it went down within 3km of a Centrica gas platform. The helicopter had flown from Blackpool Airport, touched down at two gas rigs and was on its way to a third when it was lost.

No mayday call apperaed to have been made.

One of Britain's leading aviation experts told the Times that the crash was probably caused by a sudden failure that gave the crew little or no time to react.

"The company who made the helicopter is a good one; the pilots were fully trained; all the passengers would have been trained to deal with an emergency; and the rescue services got to the scene in quite a short time," Flight International magazine operations and safety editor David Learmount said.

"So something bad must have happened suddenly and quickly."

The aircraft was carrying five passengers and two crew. Six bodies have now been recovered from the waters of Morecambe Bay on the English mainland east of the Isle of Man. The emergency services have called off their search for the missing man. All of the people on board were British.

The Millom and Morecambe gas fields are operated by

Centrica Energy subsidiary Hydrocarbon Resources on behalf of Burlington Resources.