A joint operation between Britain and Jamaica has helped cut the amount of cocaine smuggled into the Caribbean from Colombia by 80%.
An estimated 80% of cocaine in Britain originates from Colombia
Operation Kingfish targeted major drug traffickers in Jamaica, a transit point for cocaine headed for the UK and US.
Since October, the Royal Navy has intercepted 36 speedboats and seized 12 tonnes of Colombian cocaine.
UK ministers hope that it may hit the supply of crack cocaine into the UK where it fuels much gun crime.
An estimated 20% of the cocaine in Britain comes through Jamaica and 80% originates in Colombia.
Foreign Office minister Bill Rammell said that although the operation had been running less than three months, it had already proved a "significant success".
The frigate HMS Richmond and a Royal Naval Auxiliary vessel patrolled the Caribbean with the US and Jamaican coastguards.
Improved intelligence sharing as part of Operation Kingfish helped in the seizures.
The operation had contributed to a fall of 80% since the start of the year in the amount of cocaine flowing through the island, Mr Rammell said.
The drug trade has contributed to murders and shootings between rival gangs in the UK, with Scotland Yard detectives regularly travelling to Jamaica while investigating these crimes.
"This is not just about altruism. Clearly we want to help countries scarred by drugs but we are helping ourselves as well," Mr Rammell said.
Co-operation between British and Jamaican police has produced evidence which helped Scotland Yard officers on Operation Jasle - an investigation into Jamaican drugs traffickers in the UK - secure one conviction, with other cases pending, the Foreign Office said.
A Royal Navy spokesman said the navy had been pleased to be able to use its capability to help in the operation.
"There is no doubt about it, this operation has seen some success," he said.
"The Caribbean is something of a crossroads in the drug world and Jamaica identified that it was a hub for drug traffickers.
"This was a Jamaican initiative and we were very happy to help them."
He said the Royal navy's help in combating drug smuggling was "one of the things not really recognised" by the public.
HMS Richmond was involved in various duties, he added. As well as patrolling the seas, it was involved in disaster relief including major work after Hurricane Ivan struck the Caribbean during the summer.
The navy spokesman added those involved in the operation were pleased with the drug seizures.
"I'm quite certain every woman and man on board HMS Richmond was absolutely delighted, " he said.
"It is really satisfying to achieve a success against the drug traffickers," he said.
HMS Liverpool is due to replace HMS Richmond in the New Year, as Mr Rammell said: "We are in it for the long haul. If you are going to tackle this problem, you have got to keep at it."