Gardai (Irish police) and British cops are confident they have behind bars the ringleaders of a gang that masterminded a drugs operation that went wrong when the largest haul of cocaine ever captured in the Republic was seized in the seas off west Cork.

A worldwide hunt, taking in 16 countries on three continents, was launched following last year’s convictions in Cork and imprisonment of four English men for terms of up to 30 years.

At the time detectives said they believed another seven people were involved in the operation to smuggle many hundreds of millions of euro worth of cocaine from South America to Europe via Ireland.

Now three of those seven have been nabbed in the past week by police in London and charged in connection with the seizure of 440 million worth of cocaine at Dunlough Bay in West Cork in July 2007.

The seizure of more than 1.5 tons of cocaine was the biggest in the history of the state.

The latest arrests were part of a joint operation involving Gardai and the London Metropolitan Police Service.

A 49-year-old former drugs squad detective sergeant with Scotland Yard, Michael Daly, was among those held by former colleagues. He has been charged with conspiracy to supply the 1.5 tons of cocaine found in 62 waterproof sacks floating in the sea at Dunlough Bay.

Two other men, John Gary Edney, 57, from Kent, and Alan Roger Wells, 55, from Sidcup, south east London, were also arrested and charged.

The operation went wrong for the smugglers when an inflatable dinghy used to bring the shipment ashore suffered engine failure and capsized in rough seas, so the drugs were thrown into the water.

The dinghy was being used to bring the drugs to the shore from a catamaran, the Lucky Day, which had crossed the Atlantic from Barbados.

According to investigators, the cocaine originated in Colombia, from where it was shipped out through Venezuela to the Caribbean.

Daly’s brother Joseph, was one of the four arrested and jailed in Ireland following the drugs capture.

Following the first convictions, Garda drugs squad boss, Detective Chief Superintendent Tony Quilter, said they knew who the other gang members were and he pledged they would be brought to justice. He said at the time, “We will be moving against them.”

Shortly afterwards a suspect, James Hurley, number two on Britain’s Most Wanted List and who had been 13 years on the run from the law, was arrested in Holland.

The latest successes in London mean three people are still being hunted, but senior Garda sources revealed this week that they believe the main players are now all behind bars.