Cannon ball clue in hunt for sunken treasure ships

Divers searching for a fleet of sunken treasure ships believed to be carrying as much as £2.5bn in gold and silver claimed yesterday to have found a valuable clue to their final resting place.

A team exploring the mouth of the Tay near Dundee has recovered at least one artefact, a black cannon ball, which the divers believe indicates they are looking in the right area.

So far 11 potential sites have been earmarked for the location of General George Monck's 60-strong fleet of treasure-laden ships, which sank at the mouth of the river in 1651. They were laden with gold and silver belonging to the rich merchants of Angus, Fife and Perth, which Cromwell's troops plundered from the city as part of a campaign to quash royalist support in the second civil war. The ships have lain undiscovered at the bottom of the 40ft-deep channel for 350 years.

When Dundee burnt, Monck decided to take his loot back to Leith using 60 commandeered ships from Dundee's harbour. But as they set sail on September 1651 an autumn storm destroyed the fleet in the hazardous channel of the Tay estuary and all 60 ships were sunk.

Now a Coventry-based diving firm, Subsea Explorer, believes discovery is close and is applying for permission to begin a £600,000 underwater excavation of the river bed. One or two of the ships might be brought back to the surface.

"It's very exciting – we want the world to see this. It's a wonderful story," said Gary Allsop, the chief executive, who added that he was "101 per cent certain" of finding gold somewhere in the search zone. At least four sites had produced evidence of containing precious metals.

Experts are still awaiting result of tests to date the cannon ball accurately but Mr Allsop said it appeared to compare favourably with similar objects known to have been made in the 17th century. "We are having it tested, measured and weighed but it's highlighted the fact that the area we are searching in is the area we think the treasure's in," he said.