MADRID, Spain -- The Spanish government is investigating if a crime was committed by a U.S. company that said it had found $500 million worth of coins in an Atlantic Ocean shipwreck, according to Sunday news reports.

Odyssey Marine Exploration, based in Tampa, Fla., revealed on Friday they had found hundreds of thousands of colonial-era silver and gold coins in the wreck, but didn't release details about the ship or the wreck site, citing security concerns.

The Culture Ministry said it found it ``suspicious'' that the company didn't release those details, the national news agency Efe reported.

Odyssey did say that the site is beyond the territorial waters or legal jurisdiction of any country. Earlier this year, Odyssey won permission from the Spanish government to resume a suspended search for the wreck of the HMS Sussex, which was leading a British fleet into the Mediterranean Sea for a war against France in 1694 when it sank in a storm off Gibraltar.

The Spanish Culture Ministry said those permissions to the U.S treasure-hunting firm referred only to exploration and not to extraction, Efe said.

Odyssey had already begun exploration work off southern Spain for the British vessel but suspended it in 2005 after complaints from Spain.

The recovery is being attempted under a deal with the British government, the first such public-private arrangement for an archaeological excavation of a sovereign warship.

Historians believe the 157-foot warship was carrying nine tons of gold coins to buy the loyalty of the Duke of Savoy, a potential ally in southeastern France. Odyssey believes those coins could also fetch more than $500 million.

But under the terms of an agreement, Odyssey will have to share any finds with the British government. The company will get 80 percent of the first $45 million and about 50 percent of the proceeds thereafter.

Calls to the Spanish Culture Ministry on Sunday morning went unanswered.