Authorities in southwestern China have ordered three batches of milk products off shelves because they contain a chemical that killed at least six children in 2008, causing global concern over the made-in-China brand.

The health department in Guizhou province stopped the sales of dairy products made by three Chinese companies, the state-run China Daily newspaper said.

The products were found to contain melamine, which can cause kidney stones and is meant for making plastics, fertilizers and even concrete. Its high nitrogen content allows protein levels to appear higher when it is added to milk or animal feed.

Guizhou health authorities were unavailable for comment.

China executed two people in November for their role in a huge melamine-tainted milk scandal that killed at least six children and sullied the made-in-China brand.

Nearly 300,000 children fell ill in that scandal in 2008 after drinking milk intentionally laced with melamine, sold mainly in that case by the now bankrupt Sanlu Group.