An ex-official in charge of China’s controversial petitioning system, Xu Jie, has been expelled by the Communist Party, which accused him today of taking bribes, adultery and other violations. The party’s anti-graft watchdog said Xu Jie, who was deputy head of the State Bureau for Letters and Calls, was responsible for a series of cases involving the bureau “severely violating party discipline and the law”. An investigation found that Xu abused his position by demanding and receiving a large amount of bribes, it said in a statement released in its website. Xu is also an adulterer, the watchdog added, without providing details. Party officials are supposed to be morally upstanding and can be punished for morality problems, like adultery. Xu will be handed over to judicial authorities and be dealt with “in accordance with the law”. Petitioning has deep roots in China, where courts are controlled by the Communist Party, are often unduly influenced by local governments, and can be seen as beyond the reach of ordinary people. The system of petitions dates back to imperial times as a means for citizens to bring grievances to the attention of government officials by bypassing the legal system or authorities, especially at the local level. Despite international criticism, petitioners who come up to Beijing to pursue their case are often rounded up by the police and forced to return to their hometowns. Or worse still, they can be held in “black jails”, unlawful secret detention facilities where detainees can be subjected to beatings, sleep and food deprivation and psychological abuse. China is in the midst of a sweeping campaign against deep-rooted corruption launched by President Xi Jinping after he became head of the Communist Party two years ago, warning the problem is so serious it could affect the party's very survival. The southwestern province of Sichuan, which was a powerbase for the influential former domestic security chief Zhou Yongkang has emerged as one of the front lines of that campaign. Sources have told Reuters that Zhou has been put under virtual house arrest while the party conducts a graft probe, though Beijing has yet to make an announcement about his case. The former party boss of the small Sichuan city of Yaan has been sacked for taking bribes, as well as having improper sexual relationships with married women, the graft watchdog said in a separate announcement on Friday. This week, the largely ceremonial advisory body to parliament expelled a former senior Sichuan military official, Ye Wanyong, though did not give a reason. The military has been another target of the corruption fight. In March, China charged former senior army officer Gu Junshan with graft, in what is likely to be the country's worst military scandal in years. Sources have told Reuters that Xu Caihou, who retired as vice chairman of the state Central Military Commission last year and from the party's decision-making Politburo in 2012, was under virtual house arrest while helping in the probe into Gu.