The parents of children in Hunan province who took part in a study allegedly involving genetically modified rice have expressed concerns over possible health hazards.
The move comes as one of the authors of the study, Yin Shi'an, denied that the project used GM food.
Yin, a researcher with the Chinese Center for Disease Control and Prevention's Nutrition and Food Safety Institute, was listed as the third author of the study in a paper published on Aug 1 in the American Journal of Clinical Nutrition.
The paper said that in 2008, 68 children in Hengyang, Hunan province, were fed golden rice — a GM variety of rice — to test if it could help children with vitamin A deficiencies. The study was led by Tufts University in the US.
However, Liang Xiaofeng, deputy director of the China CDC, said on Tuesday that the part of the research project in which Yin participated did not involve golden rice, but that the matter is still being analyzed.
"Given that the study involved many partners and that it is a complicated matter, further investigation is still under way," Liang said.
On Sunday, Hu Yuming, a researcher at the Hunan CDC who is listed as the second author of the research paper, also denied the use of golden rice and added that he had not been asked by the journal to sign the paper before the publication.