The New Zealand Navy has made a massive drug bust on the Indian Ocean as part of a 30-nation multinational taskforce.

In the past week the frigate Te Kaha seized 260 kilograms of heroin worth an estimated $235 million.

On Saturday Te Kaha's crew boarded a dhow spotted by a New Zealand P-3K2 Orion three days earlier and after a seven-hour search, discovered 118 kgs of heroin.

Five days earlier a boarding party from Te Kaha uncovered 139 one-kilogram bags of heroin in hidden compartments on another dhow.

The Te Kaha has been working in the region since early May as part of the Combined Maritime Forces (CMF), and concluded her deployment yesterday.

Te Kaha intercepted and searched seven other dhows during patrols off the Horn of Africa and Madagascar in the past five weeks.

The seized drugs were bound for Africa and much of them would have ended up in Europe, says NZDF Commodore John Campbell.

During the same operation, Australian Navy frigate HMAS Newcastle netted 724kgs of narcotics worth an estimated $660 million.