Another mistake with food exports has jeopardised jobs and triggered calls for an overhaul of meat inspection methods.
In the fifth food trade issue New Zealand is known to have had with China this year, an error with carton labels has stopped a container of meat from entering China.
The labelling fiasco, believed to involve mutton or lamb, meant about 240 workers at Alliance Group's Pukeuri plant in Otago were sent home on Thursday. It is not known when they will be recalled.
Alliance general manager of processing Kerry Stevens said the Ministry for Primary Industries suspended Pukeuri's certification for exports to China last month because cartons in the container were incorrectly labelled.
Chinese regulations demand a label on both the inside and outside of a carton.
Meat Workers' and Related Trades Union general secretary Graham Cooke said 240 jobs at Pukeuri were now in jeopardy.
Alliance's Smithfield works, 80km away, had taken over processing sheep and lamb so the company could keep supplying China.
Cooke expected a decision in the next fortnight but feared Alliance would cut its losses by laying off the 240 Pukeuri workers. "I would expect the company will make a decision to terminate, because they're paying two groups of workers."
Alliance said it was awaiting confirmation from the ministry that action taken was satisfactory and certification would be restored. Once that occurred, the workers could be recalled.
"We regret this situation has occurred and, of course, its impact on our employees," Stevens said.
Only one container was affected and it would be returned to New Zealand. Alliance refused to say how much the meat was worth.
Cooke said the 240 Pukeuri workers and their families had an anxious wait ahead.
Troubles with exports
January 2013: Traces of dicyandiamide (DCD) found in Fonterra milk.
May 2013: Meat worth some $100 million is held up on Chinese wharves after wrong documentation used.
July 2013: 1323 containers of meat are stuck on Chinese wharves after officials there change meat import certification rules without informing New Zealand officials.
August 2013: China bans Fonterra whey protein products after bacterium Clostridium botulinum discovered.