|Odyssey arrives in Algeciras, 2007|
The Nuestra Señora de las Mercedes was sunk by the British navy in 1804 while it was traveling back from the Spain's colony of Peru with the coins. Spain filed a lawsuit against the underwater sea-explorer, demanding it return the treasure. Separate claims have also been filed by the Peruvian government and the descendants of the passengers aboard who perished when the ship went down.
In 2009, US District Judge Steven D. Merryday of Tampa ruled in favor of Spain.
Odyssey lawyers argued before the three-judge panel on Tuesday that because the ship was on a commercial mission the coins belonged to private owners and not the Spanish government. They also said that the lower court did not have jurisdiction in awarding the treasure to Spain, arguing also that Merryday didn't apply a correct analysis on "commercial activity" when he ruled in favor of Spain, Efe news agency reported.
"There are more than 200 pages of documents that prove that the majority of the coins a board the Las Mercedes were private property and were transported by a commercial fleet," Odyssey vice president Melinda MacConnel told Efe.
The Peruvian government claims the coins because it argues they were mined in the former Spanish colony. The US Justice Department has sided with Spain, pointing to the 1902 Treaty of Friendship and General Relations signed between the US and Spain in Madrid. The treaty, which is still in effect, states in part that in the case of shipwrecks, each nation will "afford the same assistance and protection and the same immunities" as they would to their own sunken vessels.
A batch of WikiLeaks US Embassy cables released recently showed that the US government had offered to help Spain recover the coins if the Spanish government helped a it recover a French impressionist painting in the Thyssen-Bornemisza Museum in Madrid which had been seized by the Nazis from the relatives of a Jewish-American citizen.
Spain didn't take up the offer.