Alan Ayres, 53, a Plymouth businessman, called a news conference at Falmouth, Cornwall, to show underwater videotapes of the vessel on the sea-bed shot in June last year by the Marine Accident Investigation Branch of the Department of Transport. The pictures show the Pescado damaged below the water line. Mr Ayres's diver was present as an observer, but Mr Ayres has kept the tapes to himself until now.
'I am making it public now because the police have decided not to allow me to be present when the wreck is raised next month,' he said. 'I'm being made the fall guy for a massive cover-up.'
The video shows 'bruising' and a 20ft (6m) 'scrape' along the hull. Most controversially, the commentary says: 'You can tell that's a submarine bow . . . that black stuff - plastic cladding or rubber cladding of a submarine.'
Mr Ayres says the voice is that of a diver hired by the MAIB. But the audio is of poor quality and it is not clear who is speaking. The MAIB would not comment.
'I have no doubt the Pescado was hit by a submarine,' Mr Ayres said. The Navy has denied it had any submarines in the area.
Fraud Squad detectives are to raise the 70ft (21m) vessel as part of a criminal investigation into her sinking. The six people who drowned were: Jo-Ann Thomas, Stephen Hardy, Sean Kelly, Neil Curry, Peter Birley and Adrian Flynn. Only two bodies have been recovered.