Panamanian police working with US authorities have made what is believed to be one of the biggest maritime drugs busts ever, Panamanian officials say.
Police and agents from the US Drug Enforcement Administration (DEA) seized a boat off Panama's Pacific coast with 19.4 metric tons of cocaine on board.
At least 12 people were arrested, including Panamanians and Mexicans.
Drug gangs often smuggle cocaine from Colombia along Panama's Pacific coast to the US, correspondents say.
National police working with DEA agents seized the Panamanian-registered boat near the island of Coiba on Sunday, a police officer told the Associated Press news agency.
The cocaine was hidden in the cargo area.
Among previous big hauls, the US Coast Guard and US Navy in 2004 found 13 metric tons of cocaine on board two fishing boats off the Galapagos Islands.
In 2001, 13 tons of the drug were seized by the US authorities on board a Belize-flagged vessel off Mexico's Pacific coast.