The Chinese government has questioned two more executives from China National Petroleum Company (CNPC) as part of a wider graft investigation into the state energy giant, said two people with direct knowledge of the matter.

CNPC and its listed unit PetroChina are at the centre of one of the biggest corruption investigations into the Chinese state sector in years.

Two more CNPC officials probed

Wen Qingshan [Photo/icpress]

Wen Qingshan, CNPC's chief accountant, and Wang Lihua, head of PetroChina's oil trading vehicle Chinaoil, were taken away by authorities last week, said the people, who declined to be identified because they were not authorised to talk to the media. Wang is also CNPC's deputy chief economist.

It was not immediately clear whether the two officials were the target of the investigation or were assisting in the broader probe.

Two officials at Chinaoil - Zheng Jun, head of crude oil trading, and a company lawyer who only gave his surname as Chen - said by telephone that the Reuters report on Wang was "totally incorrect".

"Such a thing that you reported has never happened to president Wang," said Zheng. "She is still handling daily management work."

Zheng declined to put Reuters in touch with Wang. Other attempts to reach her were unsuccessful, as were efforts to contact Wen. Calls to CNPC media officials were not answered. PetroChina spokesperson Mao Zefeng declined to comment.

One of the two sources told Reuters: "Several officials were taken away by the authorities. One is quite senior. He is CNPC's chief accountant Wen Qingshan. The other officials included ... Wang Lihua."

Two more CNPC officials probed

Wang Lihua. [Photo/cnpc.com.cn] 

Beijing stunned the Chinese energy industry in August and September with announcements that five former top executives at PetroChina and CNPC were being investigated for "serious discipline violations" - shorthand generally used to describe graft.

They included Jiang Jiemin, former chairman of both entities.

CNPC chief accountant Wen, 54, was also appointed chairman of listed Kunlun Energy in August, replacing Li Hualin, who the company said was being investigated by authorities. Kunlun Energy shares were suspended early on Tuesday. A PetroChina official said the company may issue a statement later on Tuesday.

Wang, one of the few top female executives at the state giant, has been chief of Chinaoil since 1998. The company has expanded rapidly over the years to become an influential global player in oil markets.