Beijing is investigating a senior official at the securities regulator, as it intensifies its crackdown on stock market irregularities.

Zhang Yujun, an assistant chairman overseeing brokerages and fund houses at the China Securities Regulatory Commission and who played an important role in this summer’s market rescue efforts, is the latest CSRC official to be caught up in a wide-ranging investigation. The probe has involved arrests of senior brokerage officials, and televised confessions by another CSRC official and by a leading financial journalist.

The Central Committee for Discipline Inspection said yesterday that Mr Zhang was suspected of “serious disciplinary violations”, a commonly used euphemism for corruption. The announcement came only a day after the news that officials of a brokerage involved in the market rescue effort had also been arrested.