A group of divers from south Wales have uncovered a haul of Cornish tin ingot near a shipwreck off the Pembrokeshire coast.

The three friends have already recovered a half-ton of the precious metal which has been valued at up to �20,000.

It's like finding Roman gold under a tree

Diver, Simon Donovan

However, it is believed there could be another 120 ingot on board the 18th century wreck - worth more than �1m.

The ingot was discovered half-buried in sand on the sea floor in a dive in June.

"After 21 years diving, it's the most exciting thing I have come across," said one of the trio who uncovered the ingot, Mike Lewis.

"It's like winning the lottery I suppose. A great thing for us."

A shaving of the 99% pure Cornish tin ingot has been sent off for analysis at the Department of Applied science at the University of Glamorgan.

The Receiver of Wreck, which is responsible for dealing with wreck and salvage, is also attempting the trace the original owners of the ship.

However if that proves impossible, ownership will pass to the three divers.

Simon Donovan, 37, Mr Lewis, 42, and Steve Burke, 37, are all from the Cynon Valley in south Wales.

The divers have narrowed down the possible identity to two possible shipwrecks from the 18th century.

Mr Donovan said: "It's like finding Roman gold under a tree.

"We found it by total accident - it's hard to believe.

"Usually divers go out looking for a specific wreck but this was a real bolt out of the blue."

The three are all members of the Cynon Valley Sub-Aqua Club, may have to wait for three years before the fate of the ship's cargo is decided.

If the Receiver of Wrecks decides the ship is of historical value it could go to a museum with the divers being paid the value of the cargo.