Australian customs officials have boarded a toothfishing boat which was hunted for days by the New Zealand Navy.

Last month the HMNZS Wellington followed the Kunlun and two other boats in the Southern Ocean, but had to return to New Zealand for resupply.

Australian Customs officials found the Kunlun near the Cocos Islands and boarded and searched it yesterday.

Officials say there was large quantity of frozen fish on board.

They will use information gathered to assess the legality of the boat's operations in the Southern Ocean.