President Xi Jinping has overseen a sweeping crackdown on civil society during his four years in power, charging or detaining dozens of rights lawyers and activists who authorities say are a threat to national security and social stability.
The Changsha Intermediate People's Court in central China's Hunan province released transcripts of the first hearing of Xie's case on Weibo, China's equivalent of Twitter, on Monday morning.
According to the transcripts, Xie confirmed his identity, the date he had received the charges against him, that he understood the charges, and that he would not apply to challenge the impartiality of the judge.
The court also released a short video that showed Xie saying he had not been mistreated while in custody.
It also said 40 people, including foreign and domestic journalists, attended the hearing, which it said would be an "open" trial.
Reuters could not verify independently the accuracy of the transcripts or photos released on Weibo. The court declined to comment when called and it was not possible to reach Xie.
Xie's wife, Chen Guiqiu, who is in the United States, released a statement late on Sunday that said a number of his supporters had been prevented from attending the trial.
"It looks like all parties have already prepared for this open hearing," she said. "Xie Yang is innocent, if there is an open hearing then this is to look down on the law."
Xie was reported missing by rights groups in mid-2015 and was then held without any charges being made public until January 2016, when authorities formally announced his arrest on suspicion of "inciting subversion".
In January 2017, Chen released an account that described her husband's torture while in detention. Her account was widely reported in international media.
The United Nations spoke out on Friday against the detention of his lawyer, Chen Jiangang, who had taken Xie's account of abuses and passed them to Xie's wife to release.
In March, China's state broadcaster and a number of other government-backed media outlets simultaneously released reports declaring the accounts of torture a fabrication and calling international media reports about them "fake news".