Two hundred protesting parents in Hunan Province, who fear their children were used as human guinea pigs and fed genetically modified (GM) rice in 2008 and 2009, were told Thursday their demand for answers would be met sometime next month, some parents told the Global Times.

An official surnamed Liao, who told the parents he was sent by the Hengnan County Committee of the CPC, said he would announce the results of his investigation by October 13, parents at the gathering said.

The promise came after the Ministry of Health Tuesday called for a thorough investigation into an alleged US-backed research project on GM rice in the county, amid rising concerns over the health of pupils who had allegedly been fed GM rice as part of an experiment.

"I can't wait that long," said a 42-year-old mother claiming her two children participated in the experiments. "I'm afraid the government is finding an excuse to delay the thing."

The mother said her son's feet festered while wearing plastic sandals which she connects to eating meals provided by the researchers for about one month in 2008 and another month in 2009. She said hospital treatment hasn't helped and his feet continue to fester when he wears plastic sandals.

Tao Qiulan, 42, another mother, said her son began to lose his hair this May, two years after eating the experimental meals in 2008 and 2009.

Tao said many of her sons' classmates who ate the meals have lost their hair or it has turned white.

Local officials on Wednesday said there may have been problems with the food they fed to pupils in 2008 but the food in 2009 was harmless. The parents said they were given no further explanation.

Parents interviewed by the Global Times said they were not told the meals given to their children were part of a food experiment when they signed contracts with the Jiangkou Township Center Elementary School.

Earlier reports said the experiment was reported in the American Journal of Clinical Nutrition in August. The academic paper on the journal's website provides full details of a GM rice experiment that was conducted with the consent of five volunteers, all of whom are "from the Boston area." The paper said the study's protocol was approved by the Tufts Medical Center Institutional Review Board. The lead author of the paper is listed as Tang Guangwen.

During the meeting of parents and officials in Hunan, no one was allowed to take photographs and four police officers were on site, one of the mothers told the Global Times.

Calls to He Zhongqiu, the school principal, and Lü Zhengping, a deputy chief of the publicity department of the county's Party committee, went unanswered Thursday.