BEIJING (AP) -- Executives of Chinese oil giant PetroChina Ltd. have been told to hand in their passports as an anti-corruption investigation of the industry spreads, a newspaper said Tuesday.
Authorities say five current or former executives of state-owned PetroChina and its parent, China National Petroleum Corp. are suspected of "discipline violations," a term usually used to refer to corruption.
PetroChina managers at the level of division chiefs and above were ordered to hand in their passports, the Securities Daily said, citing unidentified sources in the company. Such a move often is intended to prevent potential suspects or witnesses from fleeing while investigators gather information.
"The PetroChina corruption case has expanded beyond the company," the newspaper said.
Phone calls to PetroChina's publicity and investor relations offices were not answered.
PetroChina, with some 550,000 employees, is Asia's biggest oil producer by volume and the world's second-most-valuable energy company by market capitalization, behind Exxon Mobil Corp.
On Monday, PetroChina denied a news report that one of its vice presidents and its chief accountant had been taken in for questioning by anti-corruption investigators.
Political analysts say the investigation appears to be part of efforts by China's new leadership under President Xi Jinping to tighten control over state-owned energy companies.
PetroChina's former chairman, Jiang Jiemin, was fired last week as head of the Cabinet body that oversees China's biggest state-owned companies, the State-owned Assets Supervision and Administration Commission.
The commission's Communist Party secretary, Zhang Yi, visited rank-and-file PetroChina employees at two oilfields in China's northeast last week to affirm the ruling party's faith in their work, according to a SASAC statement.
The newspaper 21st Century Business Herald said Zhang's visit was an effort to "stabilize morale."
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