Colombian authorities will try to recover items from the San Jose galleon, which sank more than 300 years ago, with a treasure nicknamed the “Holy Grail of shipwrecks,” Business Insider reports.

The ship sank in 1708 after colliding with British warships and brought to the bottom of the sea a cargo containing more than 7 million pesos, 116 chests full of emeralds, and 30 million gold coins.

According to the Associated Press, Colombia’s Culture Minister Juan David Correa said his country will launch the first expedition to recover items from the sunken ship in April or May next year.

But the expedition will not be without controversy, as the United Nations Educational, Scientific and Cultural Organization called in 2018 not to use the sunken ship for commercial purposes, since it was only discovered in 2015.

An American maritime recovery company, however, claims half of the treasure and has sued the Colombian state to recognize its claims. The company in question, Sea Search Armada, claims to have discovered the sunken ship back in 1981 and provided the coordinates to the Colombian state on the condition that it receive 50% of the cost of any discovery.

Colombia claims that it only discovered the wreckage in 2015 and that it is not in the location indicated by the American company. But at the same time, the government refuses to disclose the exact location of the wreckage, saying that it is a state secret.

Spain, in turn, claims that the ship and the treasures on board belong to it, as they belonged to the Spanish state at the time of the sinking and are protected by UN regulations.

The Colombian government says it is preparing a “scientific mission” and does not consider the wreckage “treasures”

However, Colombia is not a signatory to the UN Convention on the Law of the Sea, which obliges member states to adhere to certain international standards, including the obligation to inform UNESCO of recovery operations, such as those prepared by the Colombian government.

But Culture Minister Correa assures that the expedition will be scientific and that the Colombian government recognizes that “San Jose is an archaeological ruin, not a treasure.”

“This is an opportunity for us to become a country at the forefront of underwater archaeological research,” he insisted in comments to the AP.

But Colombian President Gustavo Petro has made researching the wreck one of the goals of his mandate, and judging by his public comments over time, he doesn’t seem too concerned about the galleon’s scientific value.

The Bloomberg agency notes that although no one knows the exact value of the treasures left in the sunken ship, it could be anywhere from 4 to 20 billion dollars.