A public inquiry was opening today into the sinking of the trawler Gaul, which was lost off the coast of Norway in 1974.

Mystery has surrounded the loss of the Gaul for almost 30 years with some theories even suggesting the ship may have been involved in Cold War spying - a claim strenuously denied by the Ministry of Defence.

The official Formal Investigation in 1974 concluded the Hull-based vessel had ''capsized and foundered due to being overwhelmed by a succession of heavy seas.''

The wreck was discovered in 1997 and two years later Deputy Prime Minister John Prescott ordered a reopening of the Formal Investigation.

In 2002 the remains of four crewmen were discovered on the wreck by a new survey team.

Today, the re-hearing of the Formal Investigation was being heard before the Wreck Commissioner, Mr Justice David Steel. The inquiry was being opened by the Attorney General, Lord Goldsmith.

Among those represented at the hearing, which being held at Europa House, in Hull, is the Gaul Families Association (GFA). The GFA represents the families of 34 of those who died.

The relatives of the master and mate are being represented separately.

The inquiry is estimated to take about four or five weeks.