The Spanish government has claimed the rights to $500 million (£255 million) worth of treasure salvaged by the US from the North Atlantic.
In May last year Odyssey Marine Exploration retrieved some 17 tonnes of gold and silver coins from a shipwreck.
Spain is now suing the Florida-based organisation, claiming that the sunken ship was Spanish and that Spain is, therefore, the rightful owner of the treasure.
According to James Goold, a U.S. lawyer who is representing the Spanish government, Spain has proof that the vessel is a famous 19th Century Spanish galleon.
The location of the shipwreck, the nature of the treasure found at the site, and the way this was dispersed on the seabed are said to prove that the treasure had come from a Spanish warship, which British ships sunk in 1804.
The evidence was submitted to a Florida district court last Thursday.
In documents filed with the court, the Spanish government said: “The sinking of Mercedes was a pivotal event in Spanish and European history, and the site and its contents are the inalienable historical heritage and patrimony of Spain.”
Odyssey Marine Exploration has kept the exact location of the site, which has been nicknamed the Black Swan, secret, but says that it lies in international, as opposed to Spanish, waters.
Head of the treasure-hunting firm, Greg Stemm hopes that a “collaborative solution” to the long-running dispute with Spain can be found.
He commented: “It is the belief of our lawyers that Odyssey should still receive a generous salvage award.”
Stemm also told media sources that if the wreck was in fact that of the Mercedes, the Spanish government would still have to prove that it had not “abandoned” the site.
The Mercedes formed part of a squadron of four frigates that was one day away from reaching the Spanish port of Cádiz on October 5 1804, when a British fleet attacked it.
The galleon was blown apart in a huge explosion and the other three ships were seized by the British in the battle, which two months later prompted Spain to declare war on Britain.
