The advocate general is reviewing the decision to survey the wreck of the Trident, a deep sea fishing trawler that sank mysteriously without trace in 1974 and was found by chance by a group of amateur divers in 2001.

Authorities want to establish why the Trident sank off Caithness in 1974 with the loss of seven crew; a diving vessel paid for by the Department for Transport is due to start the underwater survey next week.

The review results from protests of the victims’ families, who say that cutting the vessel open on the seabed would desecrate the graves of their loved ones. Mrs Ritchie, 65, whose husband and father both died in the accident, said: ‘They should lift the vessel and test it, and those who wish to bury their dead can do so while the others can be returned to the sea.’ On Tuesday, she travelled with other widows to Downing Street to appeal directly to Prime Minister Tony Blair, handing in a file on the case.