China's ruling Communist party said it is investigating the former boss of state-run energy giant Sinopec for alleged corruption -- the latest figure in the oil sector to be probed.

Su Shulin is suspected of "serious disciplinary violations" -- normally a euphemism for corruption -- party anti-graft body the Central Commission for Discipline Inspection said on its website late Wednesday.

He is the second highest ranked official in the eastern province of Fujian and the former chief of oil giant Sinopec, second on Fortune magazine's Global 500 company list.

Sinopec's parent company CNPC was a power base for China's former domestic security chief Zhou Yongkang, the highest level victim of an anti-corruption campaign touted by China's President Xi Jinping.

Zhou was a central figure in what analysts termed the "oil faction" of influential politicians who have ties with China's powerful and lucrative petroleum industry.

He was jailed for life in June, and dozens of others in the sector have been placed under investigation.

Some analysts see the probes into the oil sector as part of efforts by Xi to assert control over China's state owned enterprises.

Ex-Sinopec president Wang Tianpu, who was put under investigation in April, was found to have taken bribes, offered benefits in exchange for his own promotion, and embezzled public assets, the party said.

Xi has pursued the anti-graft drive since taking office, vowing to go after both senior "tigers" and low-level "flies".

But critics say the drive is open to factionalism and that the Communist Party has failed to introduce systemic reforms to prevent graft, such as public disclosure of assets.

When the party announces a probe into a high level official it is almost certain that their case will later be passed over the courts where they will likely receive a jail sentence.

Su, 54 started his career in the Daqing oilfield in the northeast.

Su wrote in Communist party's mouthpiece the People's Daily in August condemning corruption, comparing Zhou and other officials to a "rotten family".

psr-tjh/fa

Sinopec