Authorities in Hunan province on Saturday denied that children in a rural school were guinea pigs in a US research project on the effects of genetically modified rice.

A research paper involving 68 Chinese primary-school children in the province was published by the American Journal of Clinical Nutrition on Aug 1, with Guangwen Tang at Tufts University in the US named as the lead author.

The unapproved experimental GM rice, widely referred to as "golden rice" and genetically engineered to produce provitamin A, was created by Ingo Potrykus at the Institute of Plant Sciences in the Swiss Federal Institute of Technology and Peter Beyer at the University of Freiburg more than 10 years ago.