China Mobile’s executive director is under investigation due to “suspected serious personal violations”, the company reported yesterday in a statement issued to the Hong Kong Stock Exchange.

The operator, China’s largest by subscribers, did not elaborate further on the probe into

Zhang Chunjiang but said it would closely monitor the situation and make further announcements when appropriate.

China Mobile was notified of the probe on Saturday.

Chunjiang is also Vice Chairman of the company’s Board of Directors. He joined China Mobile’s board of directors in June 2008. He previously served as director of China’s telecommunications ministry.

China Mobile is the country’s largest carrier by subscribers with 518 million accounts at the end of November.