Authorities appear to have tightened their hold on the largest state-owned enterprises, in the latest effort to curb corruption seen as undermining the economy and the Communist Party.
In two separate statements yesterday, Xinhua said investigations into the China Three Gorges Corporation, and the nation's two largest electricity grid operators - the State Grid Corporation of China and the China Southern Power Grid Company - had uncovered numerous irregularities and possible corruption.
A graft inquiry into Three Gorges was announced in February and its chairman and general manager were replaced.
Following that inquiry, the company said it would begin a review of all officials who had been disciplined within the past five years, Xinhua reported. It had also sealed documents relating to previous contract bids for possible investigation.
Hidden security cameras had been placed in three meeting rooms in different cities where bids were decided in order to prevent corruption and boost transparency.
Meanwhile, the National Audit Office has found more than 6.68 billion yuan (HK$8.41 billion) was misused or spent without proper oversight in a national electricity transmission project mainly carried out by the two electricity companies, Xinhua said. There were problems with 16 per cent of the spending under review, which covered a period from April to July last year.
The power project, which began in 1993, is meant to improve power distribution by building long-distance transmission lines.
The audit agency began a large review earlier this year of the activities of State Grid chairman Liu Zhenya .
It is scheduled to last until at least October.
The investigation of the power sector had "torn open a small corner" and many other investigations were likely, according to Wang Yukai , a professor at the Chinese Academy of Governance.
"The audit report sends out multiple signals. It is shocking to see so many problems with a project at the national level," Wang said.
The state-run giants have been criticised for having excessive power.