Corruption probes at the China Banking Regulatory Commission and the China Securities Regulatory Commission have cast the regulators' competence into doubt in recent months.

The stock market crash of last summer prompted investigators to probe Xiao Gang, the CSRC's deputy chairman who was removed from his post in February, and his assistant chairman Zhang Yujun, for corruption. They also found that the family members of 'politically exposed persons' or PEPs had been allowed to trade in shares illegally.

Xiao Gang is not the only high-profile regulatory figure to go this year. The State Council has just announced the abrupt departure of Guo Ligen, 61, from the post of vice chairman of the China Banking Regulatory Commission.

His passage, for which no reason seems to have been given, might not have anything to do with corruption. He has been the vice-chairman of the CBRC since 2005, having been its director-general, and the powers that be might have concluded that he was stagnating in the job. His background in the People's Bank of China as a trainer and human resources manager might not at first sight seem a good grounding for a regulatory post, but his long tenure at the CBRC suggests that he did well for many years. Voluntary retirement is another option.

Last November, however, China's main anti-corruption agency (the Central Commission for Discipline Inspection or CCDI) demoted four CBRC regulators for breaking Communist Party rules and procedures. Wang Yanyou, formerly of the CBRC's innovative supervision department, was found to have hidden his wife's status as a US citizen and accepting money and favours. He was dismissed from his post at the China Banking Association. He was also held to have committed the peculiarly Chinese offence of attending conferences without the requisite clearance. Three other men, including Jiang Fengli who headed up the Nanyang office, were demoted variously for accepting money and promoting their acolytes over the heads of others.

President Xi Jinping embarked on a massive crusade against corruption in public life three years ago. His government has lately been suppressing news of his involvement in the revelatory 'Panama Papers' débâcle.