One baby has died of kidney stones in northwest China's Gansu Province, said health officials Thursday.
It is not clear if this infant drank milk formula being investigated for causing at least 14 babies to develop kidney stones.
All of them drank milk labeled with the Sanlu brand.
The company says the milk powder could be mislabeled. It claims someone might be counterfeiting their product.
Health officials are trying to figure out if there is a link between the milk powder and the kidney stones.
So far this year, the Gansu Province had received reports of 59 cases of kidney stones in infants. There were no cases in 2007 or 2006.