The Royal New Zealand Navy-led counter-narcotics operation outside the Arabian Gulf has had a second major drug seizure in a week.

French Marine Nationale frigate FS Languedoc, operating in support of the Combined Maritime Forces (CMF) Kiwi-led Combined Task Force 150 (CTF 150), conducted a second intercept of a vessel in the Indian Ocean on Monday.

It resulted in the confiscation of 3600 kilograms of hash, valued at $US1.8 million ($NZ2.59m).

It follows its intercept and search of another vessel seven days earlier, when the frigate seized more than 1,525 kilograms of hash and 166 kilograms of methamphetamine with a combined value of more than $US5.2m.

Royal New Zealand Navy Captain Brendon Clark says with the abatement of the southwestern monsoon season, the CTF-150 is observing an increase in narcotics trafficking through the CMF area of operations.

'For the second time in a week, the French frigate Languedoc has demonstrated her expertise and professionalism in seizing a large volume of narcotics that would have otherwise been destined for market with the funds from the sale being used to fund terrorism and criminal activity,” he says.

'The continued commitment and contribution of a French Marine Nationale Frigate to CTF 150 ensures mission success.”

Criminal and terrorist organisations use the proceeds of sales of narcotics to obtain weapons, ammunitions and equipment and for training for criminal and terrorist activities.

CTF 150 is one of three task forces of the CMF. Its mission is to disrupt criminal and terrorist organisations and their illicit activities, including the movement of people, weapons, narcotics and charcoal.

CTF 150 conducts maritime security operations outside the Arabian Gulf to ensure that legitimate commercial shipping can occur freely.

The CMF is a multinational maritime partnership of 34 nations.

It exists to uphold international rules-based order by countering illicit non-state actors on the high seas and promoting security, stability, and prosperity across abouty 8.3 million square kilometres of international waters encompassing some of the world's most important shipping lanes.

The New Zealand-led multinational team took over command of CTF 150 from Canada earlier this year. The NZDF will command and staff the CTF 150 until early 2022.