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.