The U.S. treasure hunting company Odyssey Marine Exploration said on Thursday it had found two shipwreck sites near the English Channel with artifacts from the colonial period.
Odyssey, which is battling Spain over the rights to another shipwreck, said it had not identified either of the new sites.
"Both sites lie within the general area of the English Channel but are outside the territorial waters or contiguous zones of any sovereign nation," the Tampa-based company said in a statement.
"The sites both contain cannon and other artifacts which are believed to date from the colonial period."
Potential claimants would be notified if either site can be identified, said Odyssey, adding that it has filed documents in the U.S. federal court in Tampa to protect its salvage rights to the sites.
The company has been locked in a legal fight with the Spanish government over a shipwreck site it found last year with an estimated $500 million worth of gold and silver coins. Odyssey has code-named the site "Black Swan."
Spanish officials said this month they could prove it was the La Nuestra Senora de las Mercedes, a Spanish warship that was carrying treasure back from Peru when it was attacked by British warships off Spain in October 1804.
Spain claimed sole ownership of the wreck site and its contents. Odyssey, which says it has shipped most of the treasure recovered to the United States, argues it was found outside any country's territorial waters.
On Tuesday Odyssey announced a $2 million deal with the Discovery Channel to produce a television series about the company's explorations.