The Gaul sunk in heavy seas in 1974 with 36 men aboard

The Hull-based Gaul was lost in heavy seas in the Barents Sea off Norway on 8 February 1974 with the loss of 36 men.

Attorney General Lord Goldsmith, opening the inquiry into what happened on Tuesday, said it was proper that the inquiry should consider speculation that the Gaul was involved in espionage.

But he told the inquiry that the Defence Intelligence Staff, MI6 and GCHQ had all conducted investigations for him to see what material they held of relevance to the loss of the Gaul and had come up with nothing.

Lord Goldsmith said: "All three services have confirmed they have no documents which are relevant to these questions.

"There is nothing which suggests that the Gaul was engaged in any activity other than fishing on her last voyage and nothing to suggest that anyone on board her was engaged in any activity other than fishing on that voyage."

An underwater camera reveals the wheelhouse of the sunken Gaul

Investigations at the time of the sinking concluded the 18-month-old vessel had sunk after being battered by heavy seas.

But suspicions remained that it could have been torpedoed by a Soviet submarine amid claims that there was a spy on board.

Lord Goldsmith said another long-standing theory that the vessel became snagged on a secret cable would also be explored.

There had been speculation the ship had become caught on a cable which had been laid in the Cold War to monitor the movements of Soviet submarines.

In 2002, four sets of human remains were raised from the wreck, which was located in the Barents Sea in 1997.

They were identified as James Wales, Maurice Spurgeon, Stanley Collier and Clifford Briggs.

Inquests into their deaths have been adjourned until the conclusion of the public inquiry.

Six of those who lost their lives were from Tyneside.

Government 'lies'

High Court judge Mr Justice Steel, who is chairing the inquiry, may well hear evidence from defence intelligence staff, including M16 officers.

Gaul Families' Association spokeswoman Beryl Betts, whose brother Billy died on the trawler, said: "From the very beginning we believe the government knew where the vessel was and we were told lies.

"We have tried everything but every time one door opened another door closed and they have never come forward and told us the truth.

"Now, hopefully, there is a gentleman coming from M16 and we are hoping he will throw some light on the 1974 tragedy."

The original inquiry into the loss of the Gaul concluded in 1974 that the ship had become a victim of mountainous seas which had engulfed it.

Although the position of the wreck was determined by the mid 1970s it was not visited until two decades later when it was found by a survey team put together for a TV documentary.