Beijing police detained an outspoken internet celebrity as well as a journalist who has accused a senior government official of dereliction of duty, raising concerns that an increasingly tough crackdown against liberal opinion is taking place. Charles Xue Biqun, a venture capitalist better known by his alias Xu Manzi, was held on Friday along with a young woman for suspected involvement in prostitution, Beijing police said via their official weibo social media account yesterday. It also announced yesterday that Liu Hu, an investigative reporter with the Guangzhou-based newspaper New Express , was placed under police custody on Saturday for fabricating and spreading rumours, a catch-all charge used to cover acts disrupting social order. Xue, 60, was caught patronising an alleged prostitute in a residential compound in Beijing after police received a tip from residents, another weibo post said. With a following of more than 12 million "fans" on the most influential microblogging service, Xue was named in official newspapers as having links with an "online rumour-monger" arrested for "stirring trouble" and operating an illegal business two days before his detention. The Beijing Times reported that Xue had invested in a company where one of the suspected "rumour-mongers", Qin Zhihui, briefly worked. Xue has since denied having any links with Qin. Journalist Liu's wife told the Southern Metropolis Daily that he was taken away from their home in Chongqing on Saturday along with two computers and several bank cards whose accounts have been closed. On July 29, Liu alleged on weibo that Ma Zhengqi, deputy director of the State Administration for Industry and Commerce, was negligent in his public duties while working in Chongqing. The administration said it was aware of the accusation but had made no comment. Liu also shared information that raised questions over possible corruption by other senior government officials. His microblogs were later deleted. Zhou Ze, one of Liu's lawyers, said that what Liu had done did not fit in with any of the four forms of "causing trouble" as prescribed by the Criminal Law. Professor Wang Sixin from the politics and law school of Communication University in Beijing said a fresh campaign against online content had begun, but the government should take measures that can stand up to legal examination. "It's unrealistic for everything that people say online to have authoritative sources. Speech itself cannot be measured by quantitative standards," he said. State Internet Information Office director Lu Wei said recently that internet celebrities had a civic responsibility to "deliver more positive and constructive messages" and "promote virtue and trust", comments that appeared to signal tighter internet restrictions.