Wang Gongquan, a former venture capitalist and outspoken advocate for greater civic involvement on the mainland, has become the latest public figure to be swept up in Beijing's crackdown on internet dissent.
Wang, who is a close friend and supporter of arrested rights activist Xu Zhiyong, was taken away from his Beijing home at about noon yesterday, according to activists.
Activist and legal expert Teng Biao said more than 20 police officers arrived to detain the 52-year-old businessman, who was told he was to be questioned on suspicion of "gathering a crowd to disturb order in public places". Xu, the founder of the New Citizen movement, has been held on the same charge since mid-July.
Wang was one of the initiators of a signature-gathering campaign calling for Xu's release.
"It's worrying because Wang is very high profile and wealthy, an important person," Teng said.
Wang's detention comes amid a push by President Xi Jinping to "seize the ground of new media" and rein in the internet. "Big V" internet celebrities such as Wang - so dubbed because their identities have been verified by social media firms - have been scrutinised.
Last month, outspoken Chinese-American financier Charles Xue Biqun , who had more than 12 million followers on Sina Weibo, was detained on suspicion of patronising prostitutes. Wang's own account had more than 1.5 million followers before it was shut down last year.
Xiao Shu , a writer and close friend of Wang, said Wang's wife had informed him of her husband's detention. Wang was not handcuffed when he was taken away, he said.
Last month, Wang told the South China Morning Post that he was concerned about being arrested amid the crackdown.
Wang began his career as an employee of the provincial propaganda department of Jilin province in Changchun . He worked for a state-owned exporter in Haikou , before becoming a venture capitalist in 1990. He joined a protest to win the release of detained petitioners from a "black jail" in Beijing in 2011. A former partner of CDH Investments, Wang made waves in 2011 when he said he was retiring to enjoy life.
Qiao Mu , a communications expert at Beijing Foreign Studies University, believed Wang's detention was due mainly to his links to Xu, but said his detention would also send a chill through the online community.
"In the short term, it will help gag the people," Qiao said, although he speculated that the crackdown was only temporary.
Li Datong , a former journalist, said internet users were already irritated about an interpretation by the country's top legal authorities this week, which outlined what kind of online rumours could constitute a criminal offence. "This kind of across-the-board crackdown will cause much frustration among the public," Li said.
Commentator Peng Xiaoyun wrote on Sina Weibo: "Do not think silence is harmony. The greater the pressure to limit people, the more those who are restricted will gain moral and political energy. The public will lose confidence in the rule of law."
Additional reporting by Reuters and Agence France-Presse