Chinese authorities have vowed to take a zero-tolerance stance on the illegal selling and growing of genetically modified (GM) crops days after the media exposure of GM rice on sale at a supermarket in central China.

"The ministry will punish any companies or individuals who illegally grow or sell GM grains," said a statement sent to Xinhua News Agency on July 29 by the office in charge of GM food safety with the Ministry of Agriculture (MOA).

The ministry has ordered all provincial agricultural authorities to strengthen oversight and fight illegal production and sale of seeds for GM crops, according to the statement.

Chen Xiaohua, Vice Minister of the MOA, said earlier this year that China would continue to take an "active and cautious" policy toward GM crops and had set no timetable on the commercial production of GM products.