The New Zealand Defence Force has helped in the seizure of 400kg of heroin, worth about $220 million.
A New Zealand Air Force Orion surveillance plane was on patrol as part of the Combined Maritime Forces (CMF), when it spotted two ships believed to be bound for Africa and Europe.
The French ship FS Surcouf tracked down the ships and found 200kg of heroin stashed on each.
Commander Joint Forces New Zealand Major General Tim Gall said the crew provided vital information that led the French to the heroin, believed to be heading to Africa or Europe.