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

A total of 36 men lost their lives when the vessel disappeared in heavy weather off the Norwegian coast on 8 February, 1974, without sending a mayday call.

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

An inquiry into the sinking began last month in Hull, with suspicions that it could have been involved in espionage.

One theory is the Gaul could have been torpedoed by a Soviet submarine because there was a spy on board.

But Attorney General Lord Goldsmith told the start of the inquiry that Defence Intelligence Staff, MI6 and GCHQ had all failed to find evidence to support the claim.

Crew inquests

And both a Secret Intelligence Service officer and former first-mate have testified there was no spy on the ship.

The ongoing inquiry is now focusing on video footage of tests conducted on a scale model of the lost vessel.

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.