A $10 billion battle is brewing over ownership rights to a 300-year-old sunken warship believed to hold the biggest maritime treasure ever

• A US-based salvage company is suing Colombia for half a prized shipwreck's $20 billion treasure.
• The company claims it first found debris from the San José which sunk in 1708.
• But the Colombian government disputes the company's claims and says the treasure is a national heritage.

A sunken Spanish warship that lay undiscovered at the bottom of the ocean for nearly three centuries is spurring a modern-day legal battle over who has the rights to its billions of dollars worth of antique treasures.

The San José galleon, which sunk off the coast of Cartagena, Colombia in 1708, contains "the biggest treasure in the history of humanity," according to an October legal filing from the government of Colombia.

Now, more than 300 years after the San José went down, a US-based salvage company is suing the Colombian government for half the ship's treasures, claiming it first discovered the wreck in 1981.

When the San José sunk in battle against the British in 1708, the ship was carrying what was believed to be the most expensive cargo ever shipped from the New World, including more than 7 million pesos, 116 steel chests full of emeralds, and 30 million gold coins, according to court documents.

The majority of the ship's Spain-bound treasures were taken from Colombian and Peruvian mines using slave labor, NBC Today reported.

Court cases over the years have estimated the treasure is worth anywhere from $4 billion to $20 billion, Bloomberg News reported.

Current litigation over the ship stems from US-based salvage company Glocca Morra's claim that it first found debris from the San José wreck in 1981 during an exploratory exhibition searching for "shipwrecked species" and other treasures in Caribbean waters.

Glocca Morra — now known as Sea Search Armada — says it handed over the coordinates of the discovered debris to the Colombian government under an agreement that it would receive half the ship's treasure, according to the company's December 2022 notice of arbitration from.

But the Colombian government in an October response disputed many of Sea Search Armada's claims, including the notion that the San José is even located at the coordinates handed over by the company.

A 1994 report from the Colombian government said no shipwreck was found at or near the coordinates included in Glocca Morra's initial 1982 report on the exhibition, according to Colombian legal filings in the case.

Glocca Morra never even explicitly reported the finding of the San José in its 1982 report, which makes no mention of the ship by name, the Colombian government alleges. In its notice of arbitration, Sea Search Armada said the report referenced the discovery of a "large shipwreck."

"How can it be explained that a private company finds the biggest treasure in the history of humanity and fails to report it?" attorneys for the government wrote in the October response. "The answer is simple: because it did not find it."

In 2015, then President Juan Manuel Santos said the real San José shipwreck had finally been discovered, but declined to make the coordinates public, saying they were a state secret.

Colombia has since said the ship and its treasures are a national heritage item and should be kept in the country.

Sea Search Armada, meanwhile, alleges the Colombian navy simply discovered parts of the same debris field it first claimed to find in 1981.

The company is suing for $10 billion — equivalent to half the value of the ship's treasures, according to the company's estimates — under the US-Colombia Trade Promotion Agreement.

The case will play out in the Permanent Court of Arbitration, an intergovernmental organization dedicated to dispute resolution among international entities. Hearings in the case are scheduled for the coming months, according to a procedural order, and a court tribunal will make an effort to issue a decision by February. 

The race to exhume the treasure trove is heating up amid the brewing legal battle. Colombia President Gustavo Petro wants the ship brought to ground before the end of his term in 2026, the country's minister of culture told Bloomberg this month.

Minister of Culture Juan David Correa told the outlet Petro told officials to set up a public-private partnership or work with a private firm to get the ship above water as soon as possible.

Photos and video of the ship show fine china, coins, and cannons littered across the ocean floor where the San José sunk.