BEIJING — Six Chinese suspects went on trial today accused of making and selling the industrial chemical at the center of a tainted milk scandal blamed for killing six children and sickening nearly 300,000 others.

Among those in court today was the owner of a workshop that was allegedly the country's largest source of melamine, the substance responsible for the health crisis that also saw Chinese food products pulled from stores worldwide, state media said.

Police say Zhang Yujun, 40, ran a workshop on the outskirts of Jinan in eastern Shandong province that manufactured and sold a "protein powder" composed mainly of melamine and malt dextrin, the official Xinhua News Agency reported. The powder was added to watered-down milk to make it appear higher in protein content. Melamine can artificially inflate protein levels and was apparently added to watered-down milk to fool quality inspectors while boosting profits.

Prosecutors in the Shijiazhuang Intermediate People's Court accused Zhang of producing 776 tons of the additive powder from October 2007 through August 2008, making it the largest source of melamine in the country. He allegedly sold more than 600 tons with a total value of 6.83 million yuan ($1 million), the court heard.

In the same case, a second man, Zhang Yanzhang, 24, was accused of buying and reselling 230 tons of powder to others.