A liberal law professor at Tsinghua University who openly criticised Chinese President Xi Jinping has been suspended and placed under investigation by the university, according to one of his colleagues and several academics familiar with the situation. Xu Zhangrun, 56, was suspended this month after he wrote several articles criticising Beijing over political and social issues, his colleague Guo Yuhua, a sociology professor at the university, told the South China Morning Post . In one opinion piece last year, Xu questioned the personality cult surrounding Xi and the decision by the National People’s Congress to scrap the term limit on the Chinese presidency. The article, and others written by Xu critical of the president, were widely circulated online. Guo said she had spoken to Xu since he received the notice from the university telling him he had been suspended. Beijing’s top man hails new era of patriotism and rationality in Hong Kong “They spoke to him in person [as well] but I’m not sure if they actually told him the real reason” why he was suspended, Guo said. Xu was told he would be suspended from all teaching and research activities while the university conducted an official investigation, according to Guo. He would not be allowed to take on new students during the suspension period. Tsinghua University did not respond to inquiries from the Post . Phone calls and messages sent to Xu went unanswered. Friends and colleagues of Xu have called on the university to explain why the outspoken professor has been suspended. Well-known writer Zhang Yihe was one of the first intellectuals to speak out in support of Xu, posting comments on social network WeChat on Sunday questioning Tsinghua’s decision. Zhang said she did this “not because of politics or conscience” but for friendship. “I know him well. I of course must do something now that he is in difficulty – this is our tradition and morality,” she said. “Hence I want to ask the question: why has Tsinghua banned him from giving classes?” Guo suggested that Xu had been penalised because of his critical articles. “Maybe they didn’t like what he wrote, and they thought what he wrote was wrong,” Guo said. “But it’s against the law and an unreasonable thing to do.” China’s patriotism drive risks ostracising its intellectuals Zhang Qianfan, a law professor at Peking University, also expressed support for Xu. “Professor Xu was penalised by Tsinghua not because he said something radical or inappropriate, but because he made some just and honest comments that others dared not make – because free speech is in a difficult situation” in China, Zhang said. He added that Tsinghua should treat its academics properly instead of punishing them for expressing their opinions. “Tsinghua should be proud to have a scholar like Xu, but instead it imposed this unbelievable punishment on him,” he said. “This has happened because the university’s leadership wants to save their own skin, and as a result the university will pay a price and its reputation will suffer.” Zhang also called on members of the Tsinghua community and other Chinese legal professionals to stand up for Xu. “The power of thought is unstoppable,” he said. “Not many people know who the president of Tsinghua University is, but many know the university has an academic named Xu Zhangrun.”