Six men including a Briton have been arrested off the coast of Plymouth after authorities seized more than two tonnes (2,000kg) of cocaine.
The British man, from Stockton-on-Tees, and five Nicaraguans were arrested on a luxury yacht on Thursday.
The men, aged from 24 to 49, were held on suspicion of drug trafficking and remain in custody, the National Crime Agency (NCA) said.
Officers estimate the street value of the drugs is about £160m.
The group were sailing in the Jamaican-flagged Kahu when they were intercepted 80 miles off the coast, in international waters north of Guernsey.
The yacht, which had sailed from the Caribbean, was intercepted and boarded by specialist Border Force and NCA officers.
The arrests were made as part of an operation led by the NCA and supported by the Australian Federal Police (AFP) and Border Force.
Border Force’s cutter Searcher and coastal patrol vessel Alert had covertly identified and monitored the yacht’s movements, the NCA said.
Deputy director Matt Horne said: “There’s no doubt these drugs would have been sold on into communities across the UK in such ways as county lines fuelling more crime and misery.
“Organised crime groups (OCG) are motivated by money. The deprivation of these drugs will smash a hole in the OCG’s plans and ability to operate.”
Mr Horne explained that the arrests of the men transporting the drugs means the crime group will have lost trusted offenders who would have been key to their operation.
“We continue to work with partners at home such as Border Force and those abroad such as the AFP to protect the public from the Class A drugs threat,” he added.