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

The Gaul, based in Hull, disappeared off the coast of Norway on 8 February 1974 without sending out a mayday call.

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

But suspicions remain it could have been torpedoed by a Soviet submarine with claims there was a spy on board.

For years successive British governments denied the boat had been involved in intelligence gathering for the Royal Navy.

But a television documentary discovered skippers from the port of Hull had been recruited to spy on Soviet warships.

Six of those who lost their lives were from Tyneside.

An underwater camera reveals the wheelhouse of the sunken Gaul

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.

The Attorney General, Lord Goldsmith, will open the inquiry in Hull on Tuesday after a private meeting with the trawlermen's families.

It will consider evidence from two surveys of the wreck.

And High Court judge Mr Justice Steel, who is chairing the inquiry, may well hear evidence from defence intelligence staff, including MI6 officers.

Ken Collier, the son of Gaul crew member Stanley Collier, told the BBC Radio 4's Today programme: "I am looking for answers, I just want to know the truth - how she went down, where she went down.

"I am convinced the government know what happened to her.

Government "lies"

"Even though I got some of my father back, I was one of only four families who got remains back and there are still 32 who have not.

"I have three younger brothers who have been brought up without a dad."

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 MI6 and we are hoping he will throw some light on the 1974 tragedy."