Top Chinese economic official Jiang Jiemin has been sacked as head of the body overseeing state-owned companies for "suspected serious disciplinary violations", the official Xinhua news agency reported on Tuesday.
The phrase is normally used as code for corruption in China, and the move comes as the country's leaders step up a campaign against graft.
Xinhua cited the powerful Organisation Department of the ruling Communist party.
Jiang was removed from office as head of the State-owned Assets Supervision and Administration Commission (SASAC) of the State Council, it said.
The inquiry into Jiang was only announced on Sunday, and reports said it was focusing on China National Petroleum Corp (CNPC), the giant state-owned oil company he headed before being promoted to the SASAC post earlier this year.
Xi Jinping -- who took office as party chief last November and as president in March -- has warned corruption could destroy the party and has threatened to expose high-ranking officials, or "tigers", along with low-level "flies".
Jiang was the first member of the Communist Party's current 205-person Central Committee to face investigation, state-run media said.
Another former top CNPC official, Zhou Yongkang - who went on to become China's security tsar and a member of its highest body, the Politburo Standing Committee - will also face a corruption inquiry, as revealed by the South China Morning Post last week.