Xu Zhangrun, a rare outspoken critic of the government in China’s heavily censored academia, was taken from his home in suburban Beijing by more than 20 people, one of his friends said on condition of anonymity.

Xu published an essay in February blaming the culture of deception and censorship fostered by Xi for the spread of the coronavirus in China.

The law professor at Tsinghua University, one of China’s top institutions, had previously spoken out against the 2018 abolition of presidential term limits in an essay circulated online.

A friend said a man claiming to be police had called Xu’s wife, who had been living separately at a university residence, to say Xu was arrested for allegedly soliciting prostitution in the southwestern city of Chengdu.

Xu visited Chengdu last winter with a number of liberal Chinese scholars, although it is unclear if the arrest was connected to the trip, the friend said, calling the allegation against Xu “ridiculous and shameless”.