BOGOTA (Reuters) - Authorities in Colombia, working alongside counterparts in Panama and the United States, have seized 5.4 tonnes of cocaine worth $185 million, the Andean country's navy said on Wednesday.

       The drugs were found after a speedboat fled back into Colombian waters after being detected by Panamanian authorities and was pursued by members of Colombia's coast guard, the navy said in a statement.

       Following a detailed inspection of the area, members of the coast guard found the suspicious vessel with 81 sacks on board and 147 other sacks hidden in the surrounding vegetation, which together contained the cocaine.

       "If this illicit merchandise had arrived (...) in the United States or Europe, very surely that would mean 16 million doses on the streets of those countries, which would have affected the public health of the world," said Rear Admiral Juan Rozo Obregon, commander of Colombia's Caribbean naval task force.

       The drugs belonged to the Clan del Golfo criminal gang, the authorities said. The group is led by Dairo Antonio Usuga, known as "Otoniel," Colombia's most-wanted drug trafficking suspect.

       Despite decades fighting drug trafficking, Colombia remains one of the world's top producers of cocaine and faces constant pressure from the United States to reduce crops and production of the drug that has long financed Colombia's internal armed conflict.

       Colombia's security forces destroyed some 130,000 hectares (321,000 acres) of coca in 2020, and confiscated around 505 tonnes of cocaine.

       The Clan del Golfo, or Gulf Clan, is considered Colombia's largest criminal gang made up of former far-right paramilitaries. It closed 2016 with some 1,600 members, a high-ranking military official told Reuters in January.

       Earlier this week, Colombia's Defense Ministry reported that five members of Clan del Golfo were killed in the country's Norte de Santander province, including a regional leader, while another five were captured during a military operation.

       (Reporting by Oliver Griffin and Nelson Bocanegra; Editing by Peter Cooney)