A spokesman for the Department of Transport, Environment and Regions said investigators probing why the Gaul went down have made "significant findings".

As the first pictures of the wreck came through, the BBC's Paul Murphy was with some of those who lost relatives in the Gaul

The first clear pictures of the wreck show the open hatches and door, and are being examined by an investigation team and representatives of families who lost relatives in the Gaul.

Deputy Prime Minister John Prescott said: "This is a very significant find. We must now await a full assessment by the expert Marine Accident Investigation Branch team on site."

He added that discovery of the open doors "justifies our decision to go out and re-survey the end of the vessel."

The pictures are being beamed by robot submarine to a survey ship, the Mansal 18, which is carrying out the investigation.

Two relatives of the 36 crew who died are also on board the survey ship.

There have been rumours the Gaul had been spying on the Soviet fleet and might have been torpedoed.

High-definition pictures are being sent from the seabed by the ROV (remote-operated vehicle) in an attempt to establish whether the bodies of the crew are still on board and to discover why the trawler sank.

One of the relatives, Ken Collier, who lost his father on the Gaul, said he and the other families wanted to able to bury their dead and finally solve the riddle which has blighted their lives.

"We want to know the truth. The families haven't been able to get on with their lives properly because we haven't buried (the dead), and I think it's about time we did."

The vessel went down, without sending a distress signal, in February 1974.

A remote-operated vehicle is scanning the wreck

Bad weather was blamed for the tragedy, but fishermen interviewed for a television documentary last week claimed that the Gaul's skipper, Peter Nellist, had taken part in spying operations.

Vice-Admiral Sir Ray Halliday, Director of Naval Intelligence at the time of the Gaul's sinking, recently admitted that fishermen had played a covert role in the Cold War.

"Because their fishing ventures took them into areas where the Soviet navy would be passing through from time to time, they could observe them and photograph them and pass to us their course and speeds," he said.

A second inquiry, held in 1975, concluded that an open hatch door may have been responsible for the trawler's sinking.

The Mansal 18, which has been chartered by the Marine Accident Investigation Branch, will spend about three days at the site of the wreck but no attempt will be made to raise it on this trip.