Yunnan cases given extra scrutiny

In early 2000, Zhou Yongkang's mining tycoon friend Liu Han, former chairman of Hanlong Group, the largest private enterprise in Sichuan, reportedly wanted to acquire the Lanping mine. At the time, Bai Enpei was a nominee for Party chief of Yunnan province, and Zhou was Party chief of Sichuan.

With help from the two, Liu got control of the mine at a bargain rate of 150 million yuan ($24 million) for 60 percent of the Lanping mine, the largest one in Asia with market value in the hundreds of billions of yuan.

Liu was sentenced to death in August for his mafia-like acts, including instances of injury and murder.

But no hearing in the case of Liu's wife, Yang Xue, who is suspected of shielding him, has yet been opened, primarily because Yang's case is tied in with those of Zhou Yongkang, Zhou Bin (Zhou's son) and Bai Enpei, China Business News reported.

Dulong Tin Mine is also connected with the investigations of many officials, among them Zhang Tianxin, former Party chief of Kunming.

"High-voltage pressure will be applied to curb corruption," Huang Shuxian, vice-secretary of the Communist Party of China Central Commission for Discipline Inspection was quoted by Xinhua News Agency as saying.