The manufacturer of a baby milk formula that is alleged to have caused kidney stones in at least 14 infants over the past two months is under investigation, health officials in Gansu Province said on Wednesday.

The babies were hospitalized after drinking a formula made by Sanlu Group, the provincial public health bureau said.

However, a spokesman for the firm, surnamed Zhang, told the Xinhua News Agency that Sanlu was not to blame, and that it had been a victim of counterfeiting.

Representatives of the company have been sent to Gansu to conduct their own investigation, he said.

Zhang Wei, chief urologist at the No 1 Hospital of the People's Liberation Army, in the provincial capital Lanzhou, said it was possible that even more babies could have been made sick by the milk, but high medical costs might have deterred parents from seeking treatment for their children.

"It is extremely rare for babies to get kidney stones, let alone so many getting them all at the same time," he said.

Several of the parents whose children are sick said they gave their infants Sanlu milk powder because it was the cheapest available.

"We spent all our money and could afford only steamed bread to feed our babies," the parents of twins who are receiving treatment at the hospital, said.

The treatment has already cost them about 10,000 yuan (US$1,500) and they are trying to borrow more money to ensure all the kidney stones are removed, they said.

Seven babies, aged from newborn to 11 months, are currently receiving treatment at the hospital, Zhang said.

The first case was reported on June 28, he said.

Since then, all 14 of the infants admitted to hospital were unable to pass urine and had vomited, he said.

The health bureau said it is investigating Sanlu for possible connections between the milk powder and the kidney stones.

It would not say when its investigation would be completed or when the results would be published. It also declined to give the exact number of infants involved.

In 2004, 13 infants in Anhui province died of malnutrition and 171 others were hospitalized after consuming substandard milk powder that had been falsely labeled as being made by Sanlu.

(Xinhua News Agency September 12, 2008)