Officials are urgently seeking clarification from Chinese authorities, after exports from two seafood facilities in New Zealand were halted.
It has affected a Sanford facility in Havelock that processes mussels, and a Sealord facility in Nelson that processes finfish and fishmeal.
In late January, both facilities were subject to live video audits by Chinese customs.
The Ministry for Primary Industries says it was advised of the findings and suspensions on Monday evening.
It said the suspensions are due to issues around how Chinese authorities have interpreted the World Health Organisation's Covid-19 guidance, and food safety management.
Both premises are complying with New Zealand's Alert level one protocols, it said.
It's urgently trying to seek clarification.
China has been doing intensive testing of meat and fish at the border despite WHO advice stating the risk of catching Covid-19 from frozen food is low.
Around 35 percent of New Zealand's seafood is exported to China - New Zealand's largest market.