Zhou's former colleagues who have been probed

From China National Petroleum Corporation

Jiang Jiemin, former head of the Stateowned Assets Supervision and Administration Commission, was probed in September 2013. Jiang used to work at CNPC for 37 years.

Wang Yongchun, deputy general manager of the CNPC, was probed in August 2013.

Li Hualin, deputy general manager of the CNPC, was probed in August 2013. Li was a former secretary of Zhou Yongkang.

Ran Xinquan, vice president of PetroChina Company Ltd, was probed in August 2013.

Wang Daofu, chief geologist of PetroChina, was probed in August 2013.