French authorities seize 1100kg of the class A drug from a Jersey-registered vessel in the Caribbean.
Jersey's Law Officers say four suspects - three Spanish and one Colombian - were arrested on board the Jersey registered Maria Del Mar.
They're in French police custody in Martinique.
The raid happened on 26 February around 200 miles south of Barbados.
Law Officers say the haul would be worth between £55M and £77M on the street in Jersey.
French Authorities asked the Jersey Attorney General for permission to conduct checks as part of anti-drugs smuggling patrols in the region.
Attorney General Mark Temple KC says Jersey is keen to play its part in combating illicit drug trafficking, wherever it takes place:
"We congratulate the French authorities on this successful operation and confirm that we will continue to assist them.
The drugs in this case would have done enormous damage had they reached their intended markets."

Unbeaten Bulls women three more wins away from promotion
Passenger numbers already up ahead of seasonal services resuming
Jersey mixologist to head to cocktail World Championships
ATF to no longer offer biofuel after change in supplier
New images shared of updated Fort Regent plans
General Election to impact Jersey's Liberation Day events
Family Nursing and Home Care launches remote health monitoring
Hottest day of the year so far across the Channel Islands