A top Chinese oil executive is the latest senior official to come under scrutiny by China ' s top antigraft agency, as Beijing faces pressure to crack down on official corruption.

In a one-sentence statement, China ' s Ministry of Supervision said Monday it was investigating Wang Yongchun, a vice president at state-owned China National Petroleum Corp. for "severe disciplinary violations."

It didn ' t disclose more details, but such phrasing is typically used by Chinese officials when investigating cases of alleged corruption.

A CNPC spokesman declined to comment. Mr. Wang couldn ' t be reached to comment.

The move is the latest of investigations into high-ranking officials at Chinese government agencies and state-owned enterprises, amid a campaign by President Xi Jinping, who acknowledged the threat corruption poses to China ' s leaders after he took the Communist Party ' s top post last year.

Last week, China Mobile Ltd. 0941.HK +0.36% said a provincial head and former senior executive was being investigated by the Chinese government for the same reason cited for Mr. Wang. China Mobile didn ' t elaborate on what violations are being investigated. The former executive wasn ' t available to comment.

Mr. Wang, 53 years old, has run China ' s largest oil field in the northeastern Daqing region since 2009 and has been one of six vice presidents at CNPC since 2011, according to the company ' s website.

CNPC is the country ' s largest oil and gas producer by volume.

Industry officials said Mr. Wang was a potential candidate for the chairmanship of CNPC after Jiang Jiemin left the post in March to head the commission overseeing China ' s state-owned companies. But Zhou Jiping, who was CNPC ' s president, eventually was named to the top post in April after briefly serving as interim chairman.

In recent months, Mr. Wang met with energy officials visiting from Indonesia and South Sudan to discuss upstream oil-and-gas development, according to an internal CNPC newsletter.

Last week, he finished a four-day tour of CNPC ' s operations in China ' s northeastern Heilongjiang province with the company ' s No. 2 official, Liao Yongyuan, the newsletter said.

The investigation of Mr. Wang comes after the antigraft agency launched a similar probe in May targeting Liu Tienan, one of 10 deputy directors at China ' s top economic-planning body. Mr. Liu was head of the National Energy Administration from 2008 until March, when he was replaced. Mr. Liu was expelled from China ' s Communist Party this month and is under investigation for bribe-taking, according to the country ' s official Xinhua news agency. Mr. Liu wasn ' t available for comment.

Chinese officials have worked to show their enthusiasm for rooting out corruption and taming opulent official lifestyles, calling for modest meals and warning executives at state-owned firms to watch over greedy relatives.

State media have stressed the corruption push amid the trial of Bo Xilai, former Communist Party star accused of bribery, embezzlement and abuse of power. Mr. Bo defended himself against the allegations Monday as his trial concluded. A verdict is expected next month.