He disappeared again in August 2017 in an apparent attempt to escape house arrest and was subsequently taken back into custody on his recapture in September.

In 1991, inspired by a newspaper article that mentioned a plan by Deng Xiaoping, then China's paramount leader, to train 150,000 new lawyers and develop the Chinese legal system, he took a course in law.

[7] In 1989, the legislature passed the Administrative Procedure Law, which gave Chinese citizens the right to sue state agencies for the first time.

[7] He acted on behalf of a private businessman who had taken control of and redressed a troubled state-owned company when the district government used force to reclaim it after it became profitable.

In 2001, he was recognized by China's Ministry of Justice as "one of the country's 10 best lawyers" for his work in defending victims of medical malpractice and fighting for just compensation for dispossessed landowners.

[3] One significant case he spearheaded was for fair compensation for a client whose home was expropriated for a building project connected with the 2008 Summer Olympics.

[7] In the summer of 2005, Gao defended fellow lawyer-activist Zhu Jiuhu, who was accused of "disturbing public order" while representing private investors in oil wells that were seized by the government in Shaanxi.

[12] Shortly after sending an open letter to the PRC leadership that accused the government of running extrajudicial "brainwashing base(s)" for dealing with Falun Gong practitioners, he received a visit from State Security agents.

[7] On appeal in late November, the bureau demanded that Gao hand over his personal law license as well as his firm's operating permit by 14 December, threatening use of force if he failed to comply; at that time, Gao had eluded being tailed by Security, and went to north-east China to take statements from Falun Gong practitioners who alleged torture at the hands of security forces.

[7] Amnesty International alleged on 17 January 2006 that Gao narrowly escaped an assassination attempt, planned as a traffic accident ordered by Chinese secret police.

[19][20] On 22 September 2007, after writing open letters to vice-president of the European Parliament, Edward McMillan-Scott, and then to US Congress calling for a boycott of the Olympics,[21] Gao was once again taken away from his home, where he had been under house arrest, by Chinese secret police.

Gao wrote that his torturers said his case had become personal with 'uncles' in the state security apparatus after he had repeatedly publicised previous mistreatment.

It made no great impression on him, but later, when persecuted by the authorities, he found help from God and "join[ed] the brotherhood of Christians".

One month prior to his disappearance, Gao's wife and two children escaped China with the help of underground religious adherents.

[10] During the visit to China by David Miliband in March, the Chinese foreign minister, Yang Jiechi, said that Gao had been sentenced on subversion charges, but denied he had been tortured.

[33] A few days later, he met the media, appearing thinner and more subdued than in the past and said that he had abandoned his criticism of the government in the hope of reuniting with his wife and two children.

[42] Having been fed with a slice of bread and a piece of cabbage daily, he was released in bad health, but medical access was denied.

[43] Gao escaped from house arrest on 13 August 2017, spending around three weeks on the run before his recapture by the Chinese authorities the following month[6] and remaining incommunicado for at least a year thereafter.