Sun Lijun, 51, is suspected of “serious violations of discipline and the law,” euphemisms commonly used in cases of corruption, but also of violating internal Party rules.
The press release, published on Sunday night by the Inspection and Discipline Commission, did not elaborate.
Sun was, since December 2017, in charge of overseeing ministry affairs related to Hong Kong, Macau and Taiwan.
The anti-corruption campaign, launched five years ago by Chinese President Xi Jinping, has already punished more than one and a half million members of the Communist Party and investigated hundreds of senior regime officials.
Critics point out that Xi’s anti-corruption campaign served to ward off political rivals, promoted by other internal CCP groups.
Sun Lijun was last seen in public last March in Wuhan, a city of 11 million where the new coronavirus epidemic began.