Beijing - One Chinese researcher has been suspended by authorities while investigations are carried out.
China is already the world's largest grower of GMO cotton and the top importer of GMO soybeans but, while Beijing has already approved home-grown strains of GMO rice, it remains cautious about introducing the technology on a commercial basis amid widespread public concern about food safety.
The Chinese Centre for Disease Control and Prevention (CDC) investigation came after a report last month by environmental group Greenpeace claimed that a US Department of Agriculture (USDA)-backed study used 24 Chinese children aged between six and eight to test genetically modified "golden rice".
Golden rice, a new type of rice that contains beta carotene, is intended to alleviate vitamin A deficiency.
The CDC said no domestic institutions had been approved to participate in the research and that it had also asked Tufts University in the United States to help investigate the issue.
The International Rice Research Institute (IRRI) is working with leading nutrition and agricultural research organisations to develop and evaluate golden rice as a potential method to reduce vitamin A deficiency in the Philippines and Bangladesh.
The research by Tufts University and other Chinese scientists was published in the American Journal of Clinical Nutrition in August. It aimed to demonstrate that the rice could provide a good source of vitamin A for children in countries where deficiency in the vitamin is common. (here)
Andrea Grossman, assistant director of public relations at Tufts University, told state news agency Xinhua in a recent interview the university was deeply concerned about the allegations and is reviewing protocols used in the 2008 research "to ensure the strictest standards were adhered to".
"We have always placed the highest importance on human health, and we take all necessary steps to ensure the safety of human research subjects," Grossman said.
"We have always been and remain committed to the highest ethical standards in research," she said.
The Greenpeace report sparked a wave of criticism on Weibo, China's version of Twitter, with the researchers accused of a breach of ethics for testing poor, rural children whose families may not have been informed properly.
One of the Chinese authors, Shi-an Yin, has been suspended from work pending further investigation after his responses proved to be inconsistent, the CDC said.
Yin was cited by the official People's Daily newspaper as saying he helped collect data for the study but was unaware that it involved GM rice.
The second of the two Chinese researchers, Hu Yuming, denied his involvement in the research, the People's Daily said.
China, the world's top rice producer and consumer, approved the safety of one locally developed strain of genetically modified rice, known as the Bt rice, in 2009, but commercial production has been delayed.
Apart from genetically modified products, China's vast and unruly food sector is still struggling to come to grips with food safety four years after a major scandal where tainted milk powder was blamed for the deaths of at least six children.