The Communist Party has placed tighter restrictions on interrogators carrying out internal investigations of cadres suspected of graft, in a bid to better scrutinise the controversial process, observers say. Authorities can hold a suspect for a maximum of 180 days, according to new rules adopted by the Central Commission for Discipline Inspection (CCDI). Physical methods of interrogation, such as shouting, hitting and torture, already prohibited by law cannot be used. Interrogations must be videotaped, and the suspect’s family notified within 24 hours of the start of detention. The party’s system for investigating members, known as shuanggui, falls outside of mainland criminal law, and critics have long said the lack of supervision fosters abuse and gives cadres scant protection against forced confessions. But the party has increasingly relied on the system to bring prosecutions under President Xi Jinping’s widespread corruption crackdown. Statements made by suspects during the sessions and evidence uncovered can form the basis for formal prosecution. For Chinese officials accused of graft, suicide is tempting lure The rules require officers to carry out investigations in much the same way as law enforcement authorities must handle criminal detentions, which can last no longer than three months in most cases and require notification of a suspect’s family within 24 hours. Under the new rules, the standard period of detention for cadres by CCDI agents is three months, although the detention can be extended once, to 180 days. The party’s anti-graft chief, Wang Qishan, said the new regulations would force officers to initiate an investigation only in cases where they had sufficient evidence of wrongdoing. The rules were passed two weeks ago during the full meeting of the Central Commission for Discipline Inspection, but the complete text was only published on the commission’s website on Friday. Investigators are also explicitly forbidden from using intimidation or inducements on suspects. During the trial of former Chongqing party chief Bo Xilai in 2013, Bo described the tactics of investigators, who told him of the corruption trials of two other officials – one who confessed and lived and the other who fought and was executed. Communist Party seeks to reform its ‘shuanggui’ anti-corruption investigations In one notable case confirmed by the authorities, a senior engineer with a state-owned enterprise in Zhejiang province suffocated to death after he was repeatedly waterboarded by local discipline inspectors in 2013. The new rules were the first systematic regulation of shuanggui, said Zhuang Deshui, deputy director of the Clean Government Centre at Peking University. “There were rules on shuanggui before, but they were not as systematic or authoritative,” Zhuang said. “The rules were lax and not followed strictly. And we did see cases in which the suspect was hurt or even ended up dying.” The previous rules, which went into effect in 1994, stated shuanggui should last no longer than three months, but detentions could be extended indefinitely. Officers were not required to videotape questioning sessions. “[The investigators] were under no obligation to notify the relative, who usually had no clue of the person’s whereabouts,” Zhuang said. But the party was unlikely to drop the practice soon, he said. “The party apparently still needs it. It won’t be a thing of the past in the near future. But it’s expected to be under more scrutiny.”