Chinese authorities are investigating a top executive of the country's largest coal producer Shenhua, the company said, the latest suspected criminal case involving an official of a major state-owned firm.

Hong Kong-listed China Shenhua Energy Co. (CSEC) said senior vice president Hao Gui is being investigated by judicial authorities, according to a statement to the stock exchange issued Sunday.

It gave no details but said Hao was "unable to properly perform his duties".

"The board of directors of the company will make (a) further decision on the matter according to the progress of the investigation," it said, adding the listed unit was informed of the probe by parent Shenhua Group Corp.

Hao is also the vice general manager of the parent firm.

China has launched investigations into executives of several state-owned enterprises with Zhou Yongkang, the former security chief and previously head of oil major China National Petroleum Corp. among the most high-profile.

Chinese President Xi Jinping launched a much-publicised drive against corruption after he came to power more than two years ago, vowing to target both high-level "tigers" and low-ranking "flies".

CSEC said "production and operation remain normal and unaffected."

Investors were unmoved by the news. In afternoon trading, CSEC was up 1.99 percent in Hong Kong and 2.21 percent higher in Shanghai where it is also listed.