China has put six people on trial for their part in a tainted milk scandal that killed at least six children and made hundreds of thousands of others ill, Xinhua news agency reported yesterday.

Two of the accused were tried at a court in Shijiazhuang, capital of northern Hebei province and headquarters of the Sanlu Group, the company at the heart of the scandal, the agency said.

One had produced and sold more than 600 tonnes of chemical melamine mixed with malt starch to the second accused, a dairy farmer from Hebei's Quzhou county.

Melamine is an industrial compound used in plastic chairs among other things, but has been used to cheat nutrition tests.

The dairy farmer then resold some 230 tonnes to milk collectors in Shijiazhuang and three other cities in Hebei, Xinhua said.

"Some collectors added it to raw milk and sold it to Shijiazhuang-based Sanlu Group, the country's major dairy at the centre of the tainted milk scandal," Xinhua said.

After covering up the problem for several months, Sanlu admitted in September that it had sold melamine-tainted milk powder, causing kidney stones and other complications in children.

Sanlu, which halted production on September 12, has filed for bankruptcy and has some €113 million in debt, Xinhua said, citing the Shijiazhuang city government.

The Sanlu dairy group is partly owned by New Zealand's Fonterra group. Both of the accused expressed remorse during the six-hour hearing, Xinhua said. Four others went on trial yesterday in three local courts in Wuji, Xingtang and Zhaoxian counties, Xinhua said.

All were accused of adding the melamine-malt starch mix to milk and then selling it to Sanlu, the agency added.

The courts will announce the verdicts on an unspecified date.

Tian Wenhua, Sanlu's former board chairman and general manager, will go on trial on Wednesday in the Shijiazhuang Intermediate People's Court, Xinhua said.

Chinese authorities said at least six children died and around 294,000 were made ill by the milk formula.

The scandal battered faith in Chinese-made products, and led to recalls of Chinese-made diary products around the world.