Two Chinese provinces involved in a controversial human experiment of genetically-modified rice said the time and location of the test was not approved.

Authorities are investigating whether dozens of children in central China's Hunan Province were used as test subjects in a U.S.-China joint research project in 2008 that included GM food Golden Rice.

A senior official with Hunan provincial health department maintained that any human experiment of GM food in Hunan should get the approval from the provincial health and agriculture authorities. But the U.S.-China experiment did not.

Though Zhejiang Provincial Academy of Medical Sciences said it approved the ethicality of the research in 2003, the institute said the experiment did not take place during the "approved" time range between March 1,2004 and Feb. 28, 2005, the institute's deputy head Ni Ya told Xinhua.

Ni said the institute's ethical board demanded that the human test subjects shall be fully notified and give their consent before the experiment can take place.