Three people have been arrested in northwestern Shaanxi Province, as part of a fresh crackdown on melamine-tainted milk products. One suspect is a milk powder dealer, while the other two operate a company in the city of Weinan.

The Lekang Dairy Company is one of three firms blacklisted by the Ministry of Health for manufacturing and selling milk products laced with melamine. The chemical is an industrial compound that can give false positives on protein tests, but also causes kidney stones.

An initial investigation shows that the milk dealer sold 10 tons of the tainted powder to Lekang. The company then sold the corrupted commodity to a food company in southern Guangdong Province. Cracking down on melamine contamination is not new in China.

In 2008, a nationwide investigation began after at least six infants died, and 300 thousand children became ill after drinking by tainted milk products.