A Chinese commercial fishing company's been banned from working in international waters for misreporting its bluefin tuna catch.
Two vessels were fishing in water between Fiji and New Zealand last year when they were spotted by a joint Defence and Ministry for Primary Industries operation.
The company has been deregistered and hit with an $825,000 fine by Chinese authorities for being unlicensed and misreporting 100 tonnes of southern bluefin tuna as the less valuable bigeye species.
While bigeye are listed by WWF as a vulnerable species, bluefin tuna are considered endangered.
It was the first time DNA samples of fish were taken from a ship and later tested.
"The value of undertaking monitoring, control and surveillance activities on the high seas cannot be underestimated," said MPI spokesman Gary Orr.
"We have thanked the Chinese authorities for their comprehensive and thorough investigation."
New Zealand and China earlier this year agreed to work together on promoting sustainable fishing and cracking down on those who break the rules.
"New Zealand will continue to work with China and others to combat Illegal, unreported and unregulated fishing in other regions," said Mr Orr.
MPI did not name the company, but both vessels are registered to Dalian Dayang Ocean Fishy Company.