Seven people have been arrested at a dairy in northern China for producing powdered milk contaminated with the industrial chemical melamine.
Prosecutors said the general manager at the Shanxi province firm was among those accused of adding melamine to milk powder that was out of date.
Twenty-six tonnes of the contaminated product was distributed in the central provinces of Hunan and Henan.
The use of melamine in milk in 2008 killed six babies and made 300,000 ill.
Melamine is used to make plastics, fertilisers and concrete.
When added to food products it indicates a higher apparent protein content but can cause kidney stones and kidney failure.
In 2008, melamine was found in the products of 22 Chinese dairy companies - one out of every five suppliers in China.
More than 20 people were convicted for their roles in the scandal, and two people were executed.
The incident led to a worldwide recall of Chinese dairy products.
Despite a crackdown on melamine-laced milk products, some batches of tainted supplies have been found on sale since 2008.