Officially, businessman Xin Lijian, 60, was arrested in the early hours of August 22 for accounting irregularities. He runs the largest private education business in southern China, with more than 1000 staff and tens of thousands of students, focused mainly on providing affordable education to children of migrant workers who face discrimination. He is also hugely influential on social media, with his blogs receiving more than 400 million total hits, according to supporters. Xin Lijian at the University of Sydney. But the real reason for his arrest, they say, is that he is provides crucial financial and other channels of support to a constellation of leading liberal writers, economists and other public intellectuals. They include Sydney blogger Yang Hengjun and former Guangzhou newspaper editor Chen Min, who writes under the pseudonym Xiao Shu. His downfall shows how President Xi Jinping's two-year civil society crackdown is now undermining the political foundation of China's economic reforms, said Xiao Shu. "It is clear that the rulers do not believe they are compelled to bring the entrepreneur class into their social base," he said, speaking from Taiwan. China's civil society leaders are invariably tough and able to withstand personal mistreatment, but they are vulnerable to threats against family members. The most well-known example is Liu Xia, who has been under house arrest in Beijing since her husband Liu Xiaobo won the Nobel Peace Prize in 2010. But the practice of targeting family members has increased markedly since then.

Last year three siblings were arrested in the western province of Xinjiang after authorities insisted they persuade their brother, American journalist Shohret Hoshur, to quit his job at Radio Free Asia. And last month, the 16-year-old son of lawyer Wang Yu was detained at Beijing Airport en route to Australia, where he was enrolled to begin year 10 at Strathmore Secondary College, Melbourne. "I started to scream but one of the men put his hand over my mouth," said his son Bao Zhuoxuan, from his house arrest at a relative's home in Inner Mongolia. "Collective punishment is a pretty North Korean phenomenon," said Sophie Richardson, China director at Human Rights Watch. "For a country that prides itself on progress, modernisation and rule of law, these are remarkably anachronistic tactics." Xin Lijian, who was arrested last month, had sent Xin Hongyu, to study year 10 at St Spyridon College in Sydney's eastern suburbs. The son overcame patchy English to become year 12 prefect and gain entry to one of the country's most prestigious universities. He received permanent residency this year and had planned to bring his father out under the "family reunion" criteria. "It would be agonising for him, not allowed to see his family," said Hongyu. "For me, it is the feeling of being helpless."

His father had foreshadowed difficulties, after realising he had misjudged President Xi, but had endeavoured to avoid them. "I know my father, and many of his friends, had great hope in Xi Jinping," said Hongyu. "But when I was home at Spring Festival last year, he told me he'd like to keep his mouth shut, because it's dangerous, because if he didn't then something like this would happen." Initially, the family had kept quiet while prominent lawyer Chen Youxi tried tried to negotiate Mr Xin's release. But when the lawyer was prevented from seeing his client for more than a fortnight and anonymous online attackers levelled charges of "bourgeois liberalism", they were forced to take a different tack. Supporters say it too dangerous for the son to travel to or communicate electronically with China. "Almost everyone is telling me it's not safe to talk by phone," Hongyu said. Xin Hongyu comes from a family of staunch party members including his grandfather, a surgeon, who continues to receive respect for daring to treat victims during the Cultural Revolution. His father chose to be an entrepreneur and civil society activist rather than a party member, "maybe because he reads a lot".

"In the Cultural Revolution, dad got a job burning books," said the son. "He was very slow at his job because he always read the books before he burned them." Xiao Shu, the newspaper editor in Taiwan, said Mr Xin's arrest showed the Communist Party no longer aspired to retain support from entrepreneurs who hd benefited from and greatly supported the economic reform journey. "As for the average citizen and those at the bottom, they have long been abandoned, and the intelligentsia is the imaginary enemy," he said. "The social base of the regime is contracting. In the end, all it will include is the rulers themselves, and yet the rulers themselves are in disarray."