The ship was rumoured to be spying on the Soviet Navy and relatives of the lost men dispute the findings of an inquiry held in the wake of the disaster which said the ship sank in heavy seas.

We think there is a chance there may be some remains there

Beryl Betts Families' spokeswoman

Families say rumours that a Soviet spy ship torpedoed the Gaul must be investigated more thoroughly.

Judge David Steel ordered the second dive after he met with relatives, at his London chambers on Tuesday.

Gaul families spokeswoman Beryl Betts, who lost her 26-year-old brother Billy in the tragedy, said: "The first dive in 1998 did not go into all the living areas and only cameras were used to look around.

"This time there will be divers going down who will go into the areas where the first dive did not look.

"We want a second dive to be more thorough because we think there is a chance there may be some remains there and it is of paramount importance that we find them."

One of the cameras used in the 1998 search

The dive is expected to be staged in July or August by a private contractor.

The wreck of the Gaul was discovered in August 1997 by an expedition funded by UK and Norwegian television firms - the dive that followed in 1998 failed to detect any human remains.

Deputy Prime Minister John Prescott last year ordered that the original 1974 inquiry be re-opened.

The second dive must take place before the investigation resumes in November.