Chinese officials have issued warnings to seed dealers and farmers not to use unapproved genetically modified seeds in the country's main crop belt, shortly after Greenpeace said it had found widespread GM contamination in corn.
The unprecedented action by rural authorities in the past two weeks also comes as state-owned ChemChina agreed a $43 billion deal for seed and agrichemicals giant Syngenta AG , a move seen as bringing leading technology and know-how to China's fragmented seed industry as it grapples with a divisive GM policy.
China does not allow cultivation of any GM varieties of corn or other staple food crops although it does permit the import of some GMO crops for use in animal feed.
Despite Beijing's strict official position on the issue, Greenpeace last month said almost all samples taken from cornfields in some parts of the north-east, China's breadbasket, tested positive for GMO contamination.
Beijing has not explicitly commented on the Greenpeace findings, but local authorities in Liaoning, Jilin and Heilongjiang provinces issued notices to farmers and seed companies warning them ahead of the spring seed-buying season against dealing in genetically modified products.
Liaoning's seed management bureau said any business or person found engaging in illegal activity with fake or genetically modified seeds would be "strictly investigated and prosecuted."
The notice was posted on China's Twitter-like Weibo and an official at the bureau reached by phone said the notice was authentic.
A similar notice was received by a farmer in Faku county in Liaoning, said Greenpeace food and agriculture campaigner Zhang Jing. It was the first time the local government had taken such action, she said, but it is not clear how effective such a move will be.
As the world's largest grain producer and consumer, China places heavy strain on its fragmented farm sector in order to feed its nearly 1.4 billion population.
Years of intensive farming combined with overuse of harsh chemicals has degraded cropland and poisoned water supplies, leaving the country increasingly vulnerable to crop shortages.
China's crop-productivity gap is particularly evident in corn, where average yields remain over 40 percent below those of the United States due to poorer seed stock, smaller land parcels and ineffective pest management, according to the USDA.
Despite spending billions of dollars on research into biotechnology, widespread public opposition means Beijing has no timeline for the commercialisation of new GMO crops.
The policy limbo has both frustrated a handful of domestic biotech firms, and led other seed companies to simply peddle unregistered GMO seeds to farmers eager for solutions.
"We have heard that GMO corn is very popular in the west of Liaoning and a small area of west Jilin. Those areas are traditionally infested by the Asian corn borer," a moth that can devastate crops, said Liu Shi, a seed industry veteran.