The Sanlu Group, a leading Chinese dairy producer based in northern Hebei Province, admitted Friday that it had found some of its baby milk powder products were contaminated with melamine, a chemical raw material. It issued an immediate recall of milk formula made before Aug. 6. Sanlu admits contamination of baby milk powder products. Health ministry starts nationwide haul of infant kidney stone cases. Stores in China pull contaminated milk powder off shelves. China starts probe into baby powder milk contamination as more cases reported. China's health ministry says tainted milk powder causes infants kidney stone. Dairy farmers 'to blame' for poisoned milk. Goverments starts emergency response over tainted milk powder incident.