Bo Qiliang, vice president of PetroChina Company Limited, has been taken away by authorities for investigation, news portal caixin.com reported on May 16.

Bo "lost contact" on Tuesday or Wednesday, a source told caixin.com, adding that the disciplinary inspection department and the police searched Bo's office on Thursday, while detaining his secretary.

The company issued a statement on Friday night, which said that Bo stepped down as the company's vice president on April 26.