The head of a major Chinese province and former aide to disgraced official Zhou Yongkang has been placed under investigation as part of a widening probe into alleged corruption.

The party's anti-graft watchdog says Hebei province Communist Party head Zhou Benshun is suspected of "severe violations of discipline and the law." The term is a standard euphemism for corruption.

Zhou is the first serving head of a province to fall under President Xi Jinping's ongoing crackdown on corruption at all levels of government.

Zhou formerly held key positions in the central government Politics and Law Commission headed by Zhou Yongkang, a former member of the all-powerful Politburo Standing Committee who was sentenced to life in prison last month for bribery and corruption.