A former director at China's powerful economic planning agency who oversaw pricing is being investigated, financial news magazine Caixin reported on Wednesday, the latest high-level official from the department to be probed.

Cao Changqing, who recently retired as the head of the pricing division at the National Development and Reform Commission (NDRC), had been "taken in for questioning" around Sunday, Caixin said, citing sources familiar with the matter.

The NDRC did not reply to a request for comment.

The news of Cao's investigation comes five days after China's top prosecutor said a former director at the NDRC was being investigated on suspicion of "taking bribes".

President Xi Jinping has made fighting graft a central theme since taking on the job last year and has warned, like others before him, that corruption threatens the survival of the ruling Communist Party.

Caixin cited an unnamed source saying "Cao Changqing might have been implicated in the National Energy Agency corruption scandal."

In May, state media said a crackdown on China's NEA was intensifying as officials were investigated for taking bribes.

The NDRC sets policy for strategic industries, approves big investments, mergers and acquisitions and has the authority to influence prices for everything from liquor to gasoline. Its powers are so sweeping that it is often called the "little State Council."

The NDRC has been stepping up its investigations into pricing practices, launching high-profile probes into infant formula, drugs, car makers and technology firms.

In June, China formally charged Liu Tienan, a former deputy head of the NDRC, with corruption, paving the way for his trial.