The New Zealand Defence Force helped with the seizure of about $400 million in illicit drugs in the past two weeks.

This week, a Royal New Zealand Air Force P-3K2 Orion surveillance aircraft working since February as part of the Combined Maritime Forces provided information on a suspect vessel that it spotted while patrolling the Indian Ocean.

Working on the Orion's tip-off, the Royal Australian Navy frigate HMAS Arunta intercepted the vessel off the coast of Tanzania on Wednesday and found a stash of 250 kilograms of heroin.

"This is a fantastic result for the team, and highlights the NZDF's significant contribution to the multinational effort to stop narcotics smuggling and disrupting funding lines for terrorist organisations," said Wing Commander DJ Hunt, who is leading the NZDF's maritime security operations in the Middle East.


"To facilitate three major drug seizures from suspect vessels that we located and in such a short timeframe is a great testament to the investment made in training and operating an airborne surveillance and reconnaissance force."

Earlier this month, the Orion located two vessels in the Indian Ocean that were trafficking 400kg of heroin worth about $220 million.

The CMF said the two vessels, which were intercepted by the French ship FS Surcouf, were bound for Africa and Europe.

Commander Joint Forces New Zealand Major General Tim Gall said the success of the operations was in large part due to the skills of the NZDF personnel and their ability to work as part of a multinational team.

"Results such as this affirm the NZDF's standing as a valuable CMF partner. More importantly, they bring a tangible benefit to communities, given the immense harm caused by illegal drugs."

The NZDF sent an Orion and a supporting detachment to the Middle East in February to work as part of the CMF in the next 12 months.

The last NZDF Orion mission in support of the CMF helped intercept vessels attempting to smuggle drugs worth nearly $500 million during a 16-month period to December 2015.

The CMF is a 31-nation naval partnership that promotes maritime security and seeks to defeat terrorism and prevent piracy and the trafficking of people and drugs across about 8.2 million square kilometres of international waters.