Cai Xia, who had taught democratic politics at the Central Party School of the Chinese Communist Party before retiring, is the third prominent figure in recent months to be disciplined after criticising the party and its leader.

The school, which trains rising officials destined for promotion, announced on Monday that it had rescinded Cai’s Communist Party membership and retirement benefits for making remarks that “had serious political problems and damaged the country’s reputation”.

The notice on the school’s website did not specify the remarks.

Two Chinese political watchers, however, pointed to comments she made in a recording leaked online in June arguing that replacing Xi as party chief would be the first step to saving the party from itself.

In the recording heard by Reuters, a woman identified as Cai by fellow academics called Xi a “mafia boss” who turned the party into his personal tool, and a “political zombie”.

“If the Politburo Standing Committee has any sense of responsibility to the people, the country and the party, they should call for a meeting to replace Xi,” she said.

It was unclear where, when or to whom she was speaking.

Cai could not be reached for comment.

Cai is the granddaughter of a revolutionary fighter, and she had taught for four decades at the party school, giving her a solid “red background”.

China has cracked down on dissent in recent years.

Last month, a law professor at Beijing’s Tsinghua University who criticised Xi and the party was detained by police and then fired.

The professor, Xu Zhangrun, is seeking to clear his name by overturning a prostitution charge brought against him by police, his lawyer has said.

Also last month, Ren Zhiqiang, who had been the influential chairman of a state property company, was ousted from the Communist Party after he called Xi a “clown”.