The Libyan general prosecutor's office is investigating foreign and domestic oil companies over their past operations in the country, which is recovering from a civil war that ended with the overthrow of Muammar Gaddafi, the Wall Street Journal reported.
The office is probing Libyan and foreign operators in the country for possible financial irregularities, the body's deputy head, Abdelmajeed Saad, told the newspaper.
The prosecutor's office has asked the head of audit at Libya's National Oil Corp to supply it with documents related to transactions between the oil company and international traders Vitol Group and Glencore International, the Journal said.
According to the report, the investigation also includes Italy's Eni SpA and France's Total SA. The Journal said the probe focuses on the Gaddafi era, but extends through the present.
Total, Eni, Vitol and Glencore could not be immediately reached for comment.
Eni and Total have previously disclosed that their activities in Libya are under investigation by the U.S. Securities and Exchange Commission.
Eni said in its 2011 annual report that the SEC indicated the probe was in connection to "certain illicit payments to Libyan officials" possibly violating the U.S. Foreign Corrupt Practices Act.