Alleged gang bosses have claimed they were tortured by police or detained in illegal jails in order to extract confessions.
The allegations were made as the second wave of gang trials kicked off on Tuesday at the Chongqing No 2 intermediate people's court.
Chen Zhiyi and Deng Yuping, who are alleged to have run a 22-member mafia-style gang, said in court that the gang was not an organized one and they were either extorted into confessing or imprisoned in illegal jails by police.
Along with four other people with suspected connections to the gang, they are charged with 22 crimes including leading or participating in a mafia-style gang, killing three people and running illegal gambling dens.
More than 200 people heard the trial in court, mainly family members of the accused. Another 100 people gathered outside the court gate to hear live broadcast of the case.
"I admitted to the crimes after police from Fengjie county tortured me," said 43-year-old Chen in court yesterday morning.
