Six people involved in China's tainted milk scandal went on trial on Friday in four courts in northern Hebei Province.

The Shijiazhuang Intermediate People's Court accused Zhang Yujun of producing 775.6 tonnes of "protein powder" that contained melamine from October 2007 through August 2008.

The product raises the apparent protein content of milk.

Zhang sold more than 600 tonnes with a total value of 6.83 million yuan (998,000 U.S.dollars), the court heard.

Zhang Yanzhang, another man on trial in Shijiazhuang, bought and resold 230 tonnes to others.

The "protein powder" was sold to milk collectors in Shijiazhuang, Tangshan, Xingtai and Zhangjiakou cities in Hebei. Some collectors added it to raw milk and sold it to Shijiazhuang-based Sanlu Group, the country's major dairy at the center of the tainted milk scandal.

Four others also went on trial in three courts in Wuji, Xingtang and Zhaoxian counties on Friday.

Zhang Heshe and Zhang Taizhen were accused of adding 35 kg of "protein powder" to 70 tonnes of raw milk and selling the tainted milk to Sanlu, the Wuji County court heard.

Yang Jingmin and Gu Guoping were each charged with adding 24 kg of the additive to 40 tonnes and 16.7 kg to 120 tonnes. They also sold the adulterated milk to Sanlu.

The courts will announce the verdicts on an unspecified date.

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

Sanlu stopped production on Sept. 12. A bankruptcy petition for Sanlu has been filed as it faced 1.1 billion yuan of debt, the Shijiazhuang city government said on Thursday.

The Ministry of Health has said it was likely the contamination killed six babies. Another 294,000 infants suffered from urinary problems such as kidney stones.

(Xinhua News Agency December 26, 2008)