A New Zealand naval patrol ship has helped the Fiji Government to retrieve 12 kilograms of cocaine from a remote island - the second cocaine seizure from the same island this month.

The inshore patrol vessel HMNZS Taupō recovered the illicit drugs from an island that forms part of Fiji's Lau group, following a request from Fiji Revenue and Customs Service.

Early in July, Fiji authorities recovered 40kg of cocaine from the same island, which is accessible only by ship.

HMNZS Taupō, which is conducting combined maritime patrols with the Fiji Navy and other Fiji enforcement agencies, brought the cocaine cache to Suva early on Friday before resuming its fisheries patrol.

The Fiji Police Force tested the retrieved packages and confirmed that they contained cocaine.

Taupō commanding officer Lieutenant Benjamin Flight said the joint maritime patrols were "focused primarily on enforcing regulations for inshore fishing", but also supported other Fijian agencies when required.

Fiji Revenue and Customs Service chief executive Visvanath Das said the joint operation sent a clear message.

"Fiji authorities are determined to protect our country's borders and will not allow it to be used as a transit or a destination for illegal drugs," he said.

"Surveillance in coastal communities and seas is an ongoing challenge for Customs. However, with the assistance and co-operation from island communities, we can protect our borders from illicit trade."

The NZ Defence Force said it was the second consecutive year it had deployed an inshore patrol vessel to help Fiji patrol its exclusive economic zone of over 1.2 million square kilometres.