A vice-chairman of the nation's top political advisory body is being investigated for "disciplinary violations", the Communist Party's anti-graft watchdog said. Su Rong, vice-chairman of the Chinese People's Political Consultative Conference, is under suspicion of violating party rules and state laws. Such violations typically refer to corruption. Su is the most senior serving official to be probed for graft since President Xi Jinping took the helm in 2012. Su is one of 23 vice-chairmen of the CPPCC, a political advisory body of more than 2,000 delegates that is part of the party-controlled government structure. Its chairman and vice-chairmen enjoy the ranking of state leaders. Su served as party chief in Gansu and Qinghai provinces, then served as Jiangxi party boss from 2008 until March last year, when he was elevated to the national leadership. The party's Central Commission for Discipline Inspection said in a one-line statement on its website yesterday that Su was under suspicion of violating party rules and state laws. Details about Su's circumstances were not provided. Rumours that Su was under investigation began circulating last year when the former wife of Zhou Jianhua, who chaired the standing committee of the People's Congress of Xinyu in Jiangxi province, tipped off visiting graft-busters that Su's wife was suspected of corruption in several land and construction deals, according to a report by Caixin Media yesterday. Zhou was handed a death sentence, suspended for two years, in January for accepting more than 14 million yuan (HK$17.6 million) in bribes. Caixin reported that Zhou had claimed he was set up by Su for blowing the whistle on his wife. Su was last seen in public during a trip to Qinghai last weekend. While rumours of his downfall were rife in February, Su made a high-profile appearance and talked to overseas journalists on the sidelines of the National People's Congress in March, denying he was implicated in corruption. A number of senior Jiangxi officials have been investigated or sentenced in recent months, including Chen Anzhong , former deputy director of the standing committee of the provincial People's Congress.