26 Jan 2010 --- In a repeat of the original milk safety scandal of 2008, when six children died and 300,000 were sickened after drinking melamine contaminated baby formula, authorities in the south west China province of Guizhou, have yet again found traces of the industrial chemical which is used to manufacture fertilizers and plastics, in the milk products in China.

The announcement calls into question the effectiveness of a crackdown launched by Chinese officials to improve product safety after a number of scandals, including the contamination of baby formula in 2008 and the recent discovery of the toxic metal cadmium in cheap jewelry.

Frozen milk products and cartons of milk dating from early 2009 were taken off the shelves after health inspectors tested them and found melamine, said Ling Hu, a Guizhou provincial government spokeswoman.

The contaminated products belonged to three companies, Zibo Lusaier Dairy, Liaoning Tieling Wuzhou Food and Laoting Kaida Refrigeration, of which Laoting Kaida Refrigerationhad been involved in the 2008 scandal as well.

Melamine can be added to watered-down milk to make it appear to have a higher protein content. If ingested in sufficient quantities it can cause kidney failure and kidney stones.

The companies involved in the latest recall blamed the contamination on milk powder they had bought as a raw material to add to their products, state media reported.