About 1,300 containers of New Zealand meat exports were again held up by Chinese customs barely two months after the Kiwi government made a mistake in the issuance of their export certification. This time the cause of the delay was China's new sudden change of rules.

Nathan Guy, Primary Industries minister, said New Zealand received a tip off that China had issued new rules for NZ meat certification on Thursday. "In the last 48 hours we have sought clarity around the impacts of those requirements and officials have negotiated their implementation," he said.

China's new rules require that meat exports must have been first approved by vets in New Zealand throughout the processing stages before it actually gets loaded to containers.

The new rules, which officially takes effect on July 8, affects some 30,000 tonnes of meat believed to have been exported to China since June 1. The release of these batch by the Chinese customs into the market are expected to get delayed until all updated documentation has been received and accepted by Chinese officials.

The process can take about a week, according to the Ministry for Primary Industries (MPI).

But Damian O'Connor, Labour Primary Industries spokesman, in a report by the New Herald, said the new rules "could have serious ramifications for the industry."

"The Government may have to reverse its programme of deregulation for meat inspection in freezing works across the country."

MPI said it only found of the new Chinese regulation when it heard a New Zealand container was stuck on China's port Dalian.