BEIJING (AP) — Chinese state media say the Communist Party has fired the head of a body that oversees major state-owned companies and who is being investigated for corruption likely linked to the country's biggest oil company.

Xinhua News Agency said Tuesday the party has dismissed Jiang Jiemin from his positions as director and deputy party chief of the Cabinet's commission that runs state companies.

Jiang formerly was chairman of the state-run China National Petroleum Corp., which has been the target of a sweeping graft investigation that also has netted four top executives in recent days.

News reports also say China's top leaders have taken the unusual step of endorsing a corruption investigation into Zhou Yongkang, a former security czar and CNPC general manager.