New Zealand’s Defence Force says a North Korean ship was observed engaging in a possible transfer of illicit goods at sea.

New Zealand’s military said a surveillance aircraft observed what it suspected was North Korea breaking international sanctions in a “possible ship-to-ship transfer of illicit goods”, while conducting monitoring over the Yellow Sea and East China Sea.

New Zealand’s Defence Force said on Tuesday that the exchange of goods at sea between vessels was captured by one of its long-range P-8A Poseidon reconnaissance aircraft in international waters near North Korea.

The exchange was observed among 35 “vessels of interest” in the area while its surveillance aircraft was patrolling for possible North Korean violations of United Nations sanctions at sea, the Defence Force said.

“The evidence captured of activities that were occurring in the East China and Yellow Seas allows authorities to take action against ships that may still be operating in contravention of [UN resolutions],” New Zealand’s Air Component Commander, Air Commodore Andy Scott, said in a statement.

New Zealand did not disclose what goods were transferred in the exchange on the high seas.

North Korea typically uses ships to smuggle refined petroleum imports and to export its coal, iron ore and sand, which help fund its nuclear and ballistic missile programmes, New Zealand said.

North Korea has been under UN sanctions since 2006 after carrying out its first nuclear weapons test, according to the Centre for Arms Control and Non-Proliferation.

UN sanctions were significantly expanded in 2016 and 2017 to include a range of exports and ship-to-ship transfers.

Despite the restrictions, North Korea continues to trade goods with a handful of countries.

Its main customer is China, but it has also been known to sell weapons to Iran and Russia in exchange for oil or hard currency, according to the Georgetown Security Studies Review.

New Zealand has been a member of the US-led Pacific Security Maritime Exchange since 2018, which monitors North Korea’s violation of international sanctions through smuggling and illicit maritime activity.