BEIJING -- Chinese authorities have found dairy products in at least two provinces tainted with an industrial chemical that killed six babies and sickened thousands more in 2008, state media said Friday.

The discovery suggests toxic milk remains a lingering danger in China despite a crackdown two years ago that saw dozens arrested and two people, a dairy farmer and a milk salesmen, executed.

Some of the recently found milk was powder that state media said was likely stockpiled instead of destroyed two years ago.

Melamine is added to watered-down milk to make it appear rich in protein in quality tests that measure nitrogen, found in both the melamine and protein. Health problems from the chemical include kidney stones and kidney damage.

In June authorities found 64 tons of raw materials for making milk powder and 12 tons of finished powder tainted with melamine at a factory in the far western province of Qinghai, the official Xinhua News Agency said. In a separate case, they said they seized about 1,000 packets of tainted milk powder in the northeastern province of Jilin.

Xinhua said the owner and a production manager from the factory in Qinghai have been detained. The report said some of the milk products at the Dongyuan Dairy Factory had 500 times the legal limit for melamine. It did not say whether there were any reports of people getting sick from the dairy's products.

The report said some of the material was believed to be old powder that should have been destroyed in 2008 amid a crackdown on tainted milk but that it was stored instead.

Xinhua said the Dongyuan Dairy Factory in Qinghai purchased the problem goods from Shaanxi and Hebei provinces and sold it in Jiangsu and Zhejiang - a supply chain that suggests melamine-tainted milk products could still be available in many parts of the country.

The problem powder in Jilin was produced in neighboring Heilongjiang, the report said.

At least six children died and nearly 300,000 children fell ill after consuming tainted infant formula in 2008. (AP)