Beijing - Chinese health authorities are investigating milk powder as a possible cause of high hormone levels found in several infants who appeared to show signs of premature sexual development, state media said.
Experts have started testing samples of milk powder produced in 1998 by the dairy company Synutra International in the eastern city of Qingdao, the official China Daily quoted Health Ministry spokesman Deng Haihua as saying.
Deng promised "timely publication of the investigation results," the newspaper said.
The investigation follows reports that at least four baby girls had developed breasts and showed high levels of the hormones estradiol and prolactin.
All four had regularly consumed infant milk formula made by Synutra, the reports said.
But no tests had been performed on the milk powder and the company insisted that its products were safe, the newspaper said.
New Zealand's giant milk company Fonterra Cooperative Group, which has supplied Synutra, said it had abided by strict legislative controls on the use of hormonal growth promotants (HGPs) in New Zealand and they were not allowed for milk cows.
A major milk scandal hit China in 2008 when tests found that many milk products, including those of most leading brands, contained high levels of melamine, an industrial chemical used to artificially boost protein levels and raise producers' profits.
The tests followed reports in late 2008 that thousands of infants had developed kidney and other health problems after consuming several popular brands of powdered milk.
The government later said at least six infants died and up to 300 000 were sickened by contaminated milk powder.
Chinese courts have tried at least 21 people accused of involvement in the 2008 milk scandal. Two of them were sentenced to death and executed in November.
But state media have reported several new cases of melamine-contaminated milk since 2008. - Sapa-dpa