Keighley's "Goldfinder" Keith Jessop, is to help solve a 28-year-old mystery surrounding the sinking of a Hull trawler.

Mr Jessop, 67, one of the most famous wreck hunters in the world, is to join a multi-million pound expedition to explore the Gaul.

The operation is being carried out by the Government's Marine Accident Investigation Bureau after a formal investigation into the ship's loss was reopened by Stephen Byers, Secretary of State for the Department for Transport, Local Government and the Regions.

Mr Jessop will be re-visiting the wild waters of the Berants Sea where he scored his biggest triumph - the recovery of £40 million of gold bullion.

In 1981, he retrieved the ingots from the battle cruiser HMS Edinburgh, which was torpedoed and sank in 1942.

The Gaul went down on February 8, 1974, in a force nine gale, taking with it the 36-strong crew.

Since then it has been the subject of controversy, many people believing it was sunk by forces from the former Soviet Union because it was on a spying mission.

The vessel is in the same area as HMS Edinburgh, but at 900ft, is 100 feet deeper.

Today, Barry Tindall, the solicitor representing the Gaul Families' Association which invited Mr Jessop to take part, said: "Mr Jessop is joining the expedition because of his expertise in deep sea exploration and his knowledge of these waters.

"He has particular knowledge of using remote operated vehicles.

"We originally wanted a manned dive, but the Government said it was too dangerous.

"But Keith went down there 20 years ago and brought back gold and then the Government described it as a great British achievement."

He said the Gaul Families' Association wanted to find out if crew members' remains were still in the trawler.

It was also hoped to explore the cabin to see if it was carrying extra equipment, which might suggest it was used on a spying mission.

The operation - expected to take place in July or August - will be filmed for a TV documentary by Norman Fenton, who discovered the resting place of the Gaul during an expedition funded by British and Norwegian TV companies in August 1997.

An inquiry in 1974 concluded that the trawler capsized and foundered after being overwhelmed by heavy seas.

But crew members' families never accepted the verdict and after the wreck was discovered, Deputy Prime Minister John Prescott asked the Marine Accident Investigation Bureau to carry out an underwater survey.

That investigation concluded that the Gaul appeared to have sunk due to "downflooding" through open weathertight doors and hatches on the trawl deck after being hit by several very large breaking waves but it recommended that the Government reopened a formal investigation into the Gaul's loss due to the "new and important evidence" that had been found.