The Hull-registered Gaul sank off northern Norway in February 1974, with the loss of all 36 seamen aboard. It was rumoured to be spying on the Soviet Navy.

Government scientists are hoping to take DNA samples from the remains buried 25 years ago, and compare them with samples from relatives of the trawler's crew.

'No connection'

But the latest two bodies exhumed were found to be female.

An official in northern Russia said it was likely none of the graves were connected with the trawler.

Lyubov Timokhina, deputy head of administration of Pechenga District, said the graves had been listed as unmarked.

"After 25 years there is a risk of turning over somebody else's grave. The cemetery's records show that these graves were designated as unmarked," he said.

Spy mission

There has been intense speculation that the trawler was a spy ship and was sunk by the Soviet navy, or struck by a Nato submarine.

A Marine Accident Investigation Branch (MAIB) report in April found it had capsized in high seas, a finding disputed by relatives of the lost men.

None of the bodies of Gaul's crew have ever been found and the disappearance of the trawler is a mystery of the Cold War era.

If scientists prove the men buried in Russia were on the Gaul it might still lay to rest the theory, put forward by relatives, that the crew were captured by the Soviet Navy and could be alive in jail somewhere in Russia.

'Difficult and sensitive'

British officials had thought the bodies were once Gaul crewmen because post mortem reports released after the fall of Communism show at least one had a tattoo in a Western language.

Deputy Prime Minister John Prescott said the "difficult and sensitive" operation was designed to ease the uncertainty for the families of those who died.

The DNA samples will be taken to laboratories in Wetherby, Yorkshire, for analysis.

A formal investigation into the sinking of the trawler was reopened following the MAIB report, which was itself sparked by the discovery of the wreck of the Gaul in August 1997.