A profile in a magazine affiliated with the party's main mouthpiece portrays Jiang Jiemin, once one of the most powerful men in the nation's oil industry, as humble and disciplined early in his career, but who later grew controlling and demanding. Jiang, the former director of the State-owned Assets Supervision and Administration Commission and ex-chairman of China National Petroleum Corporation (CNPC), the country's biggest oil company, has been under investigation since late last month for serious discipline violations, a party euphemism for corruption. Jiang was born into a rural family in Jiangjia village in Yangxin county, Shandong province, and earned a reputation for self-control, austerity and diligence, according to the profile in Global People , a monthly magazine tied to the Communist Party's People's Daily . A village resident was quoted as saying Jiang's father, a former director of a county government agency overseeing logistics, never took the government car he was given for work. Another local added: "His father was often seen riding a bike home or attending crops on the family land." After becoming a senior executive at a state-owned company and a government official, Jiang keep a low profile when he went back to the village for visits, preferring to park his official car on the outskirts of the community and walking home. One of Jiang's former classmates recalled Jiang as a smart pupil at school in the 1970s, adding "he was almost always the top scorer in exams". Jiang left his village at age 17 and went to Dongying, which lies in the Shengli Oilfield, and spent eight years toiling away at difficult jobs before moving into middle management. He remained in the business, rising to chairman of CNPC in 2006, a position he held until March this year, when he was appointed head of the assets commission. Later in his career, Jiang developed a reputation for being controlling, demanding and nepotistic, the profile said. Jiang attracted scrutiny after an audit of his performance at CNPC and elsewhere, although investigators have yet to detail the extent of their concerns.