Tampa, Fla. ? Deep-sea explorers who found $500 million in sunken treasure two years ago say they have discovered another prized shipwreck: A legendary British man-of-war that sank in the English Channel 264 years ago.

The wreckage of the HMS Victory, found below about 330 feet of water, may carry an even bigger jackpot. Research indicates the ship was carrying 4 tons of gold coins when it sank in a storm, said Greg Stemm, co-founder of Odyssey Marine Exploration, ahead of a news conference today in London.

So far, two brass cannons have been recovered from the wreck, Stemm said. The Florida-based company said it is negotiating with the British government over collaborating on the project.

“This is a big one, just because of the history,” Stemm said. “Very rarely do you solve an age-old mystery like this.”

Thirty-one brass cannons and other evidence on the wreck allowed definitive identification of the HMS Victory, 175-foot sailing ship that was separated from its fleet and sank in the English Channel on Oct. 4, 1744, with at least 900 men aboard, the company said. The ship was the largest and, with 110 brass cannons, the most heavily armed vessel of its day. It was the inspiration for the HMS Victory famously commanded by Adm. Horatio Nelson decades later.

Odyssey was searching for other valuable shipwrecks in the English Channel when it came across the Victory. Stemm wouldn’t say exactly where the ship was found for fear of attracting plunderers, though he said it wasn’t close to where it was expected.

Federal court records filed by Odyssey in Tampa seeking the exclusive salvage rights said the site is 25 to 40 miles from the English coast, outside of its territorial waters.

A Ministry of Defense spokesman said Sunday the government was aware of Odyssey’s claim.

“Assuming the wreck is indeed that of a British warship, her remains are sovereign immune,” he said on condition of anonymity in keeping with government policy. “This means that no intrusive action may be taken without the express consent of the United Kingdom.”