Four executives of the Sanlu Group, the major dairy at the center of China's tainted milk scandal, went on trial today at a court in Shijiazhuang, capital of northern Hebei Province.

The Shijiazhuang Intermediate People's Court accused Tian Wenhua, Sanlu's former board chairwoman and general manager and three other executives of producing and selling fake or sub-standard products.

The court opened at 8 am The three other executives are former deputy general managers Wang Yuliang and Hang Zhiqi, and Wu Jusheng, a former executive in charge of the firm's milk division.

Wang was in a wheelchair after losing the use of his legs in a suicide attempt, according to court sources.

The four defendants were arrested on Sept. 26.

Tian told the court that she learned about the tainted milk complaints from consumers in mid-May, and then the company set up a working team led by her to handle the case.

Sanlu Group submitted a written report about the problematic milk powder to the Shijiazhuang city government on August 2, she said.

If convicted of producing and selling fake or substandard products, defendants can be imprisoned for terms up to life.

Prior to the trial of these four, 17 people have gone on trial on charges of producing, adding melamine-laced "protein powder" to milk or selling the tainted milk to Sanlu or other dairies.

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

Sanlu Group stopped production on Sept. 12. A bankruptcy petition for Sanlu has been filed in the face of an 1.1 billion yuan debt.