By the BBC's Greg Morsbach

British naval experts and American marine archaeologists have discovered a sunken 17th Century warship near the Straits of Gibraltar in the Mediterranean.

They say the remains of the ship are very likely to be those of the HMS Sussex, a British naval vessel, which may contain treasure worth billions of dollars.

The treasure was meant as a bribe to win Savoy's support

American explorers working for a Florida-based company, Odyssey Marine Exploration, say they located HMS Sussex on the basis of items retrieved from the seabed.

Remote-controlled robots recovered important pieces of identification - a cannon and ball lying on the bottom of the sea, 800 metres down.

Marine historians at the British Ministry of Defence are almost certain they are dealing with the Sussex.

Documentary evidence led historians to conclude the ship was carrying 10 tonnes in gold or 100 tonnes in silver coins in her hold on her final voyage in 1694.

The value of her treasure could total $4bn.

Historical value

The Sussex sank in a violent storm on her way to the Duke of Savoy whom Britain needed as an ally in a war against France.

Even if the wreck does not yield treasures, it is still a major historical find, as Lieutenant-Commander James Jenkin, a spokesman for the British Ministry of Defence, explains:

There are very few examples in the artefact field that exist from a naval wreck of that period

Lieutenant-Commander James Jenkin British Ministry of Defence

"There are very few examples in the artefact field that exist from a naval wreck of that period and clearly we would be very interested in any recovered.

"If, indeed, the wreck is HMS Sussex then one can expect an increasing amount of public interest."

The Odyssey salvage experts have already offered their services to the Ministry of Defence.

They started looking for the Sussex in 1995.

The hunt has cost them $3m so far.

The British Government and Odyssey are currently planning the logistics for a joint salvage operation.

Just how well the Odyssey salvage team will do financially has not been decided yet.

It is standard practice in the salvaging business for the finder to receive the lion's share of any valuables.

Odyssey could therefore expect to receive a fortune.