Two more senior executives of state-owned enterprises have been placed under Communist Party investigation as a major corruption probe widens. Both investigations appear to be linked to China’s highest level graft probe in recent history centring on Zhou Yongkang, who until earlier this year served on the party’s top decision making body, the Politburo Standing Committee. President Xi Jinping gave the go-ahead for an investigation into Zhou in August. Jin Jianping, the former chairman of Tianjin Gas Group was detained on September 5 in Xianghe, Hebei province, the 21st Century Business Herald reported on Thursday. He has since been placed under shuanggui, a form of detention for party members under investigation for disciplinary violations, the economic daily said citing unidentified sources. Jin’s detention came three days after the group’s Hong Kong-listed subsidiary Tianjin Jinran Public Utilities unexpectedly announced his resignation as chairman of its board in a stock exchange filing. The Zhejiang native resigned “owing to work reallocation,” the statement said. “There is no matter relating to his resignation that will need to be brought to the attention of the shareholders,” it added. The report by the Herald suggested that Jin knew of a pending investigation and had attempted to leave the country. The report said Jin’s investigation appeared to be linked to a wider probe into graft allegations at China National Petroleum Corporation, the nation’s largest oil producer. Zhou headed the state-owned company in the 1990s. In another development, the former chairman of the Bank of Chengdu Mao Zhigang had also been placed under shuanggui, the financial news outlet Caixin reported on Thursday. Mao was removed from his position earlier this year. Mao served as deputy head of the Chengdu Economic and Information Commission between 1998 and 2001, which coincided with disgraced provincial party secretary Li Chuncheng’s tenure as the city’s deputy mayor and Zhou’s tenure as provincial party secretary. Li is being investigated on allegations of graft, state media said in December. Mao also served on the board of the municipal Chengdu Industry Investment Group along with its chairman Dai Xiaoming, who was taken away by party investigators in September last year.