Baby formula from China is illegal in the United States and should not be used, U.S. regulators warned on 11 September after Chinese officials blamed tainted formula for the death of an infant.

U.S. Food and Drug Administration officials said it was possible that some formula from China may have slipped into markets serving Chinese consumers in the United States even though its sales are prohibited.

The agency advised consumers not to purchase or use baby formula from China if they do see it. "We have some concerns that there may be some supplies of infant formula that may have gotten into the country illegally and may be in specialty markets that serve the Chinese community," Janice Oliver, deputy director of the FDA's Center for Food Safety and Applied Nutrition, said in an interview.

An US FDA probe in 2004 found Chinese formula on the shelves of an ethnic retailer in the United States, Oliver said. The FDA has no evidence of Chinese supplies in U.S. stores now.

Chinese authorities on Thursday said tainted, milk-based formula killed one baby and caused kidney stones in dozens of others who may have drunk the same product.

Contaminants were found in Sanlu-brand milk formula, China's Ministry of Health said. The Sanlu Group recalled milk formula made before August 6. The FDA's Oliver said agency officials were concerned the Chinese formula may be tainted with melamine, the contaminant found in pet food ingredients from China and linked to the deaths and illnesses of hundreds of cats and dogs in 2007.

U.S.-approved baby formula is safe, Oliver said. The FDA contacted the five approved makers of milk-based formula and was told they do not use ingredients from China, she said. "There is no threat of contamination in the domestic supply of infant formula," Oliver said.The U.S.-approved makers of milk-based baby formula are Abbott Nutrition, Bristol-Myers Squibb unit Mead Johnson Nutritionals, Nestle USA, PBM Nutritionals and Solus Products.