Libya has started investigating foreign oil companies over their past relationships with the former Muammar Gaddafi government, an investigator with the ruling National Transitional Council (NTC) said Monday. Salem Qanan, who sits on the NTC's Oil Committee, said the government had requested documents from Libya's National Oil Corporation (NOC), which is in charge of contracts between private companies and the state. Qanan said his committee had received information from people who had worked in the energy sector during Gaddafi's rule that led it to believe there was reason to suspect the contracts agreed during that time. “There are some suspicions over some contracts that were made by the NOC and foreign companies which seem to have been influenced by Saif Al-Islam Gaddafi,” he said. Saif Al-Islam is one of the sons of the former Libyan leader, who is in detention in Libya and wanted for trial both by the Libyan authorities and the International Criminal Court. Educated at the London School of Economics, Saif Al-Islam and his aides were an important point of contact in Libya for many Western governments and companies. During Gaddafi's four decades of rule, many of the world's majors either operated in Libya or signed oil deals with Tripoli. In October, Libya pledged a probe of Gaddafi-era oil deals. Analysts said the investigation had the potential to spread panic among foreign players and even delay the return to normal oil output. “The investigation is part of due diligence and a routine process to make sure there were no irregularities either with the old regime or the new one,” NOC marketing manager Ahmed Shawki said. Industry sources have long expected a wide-scale probe of oil deals by the new rulers in Libya, who are under pressure to root out any graft from the Gaddafi era. Uncertainty about the contracts is likely to delay the oil industry's return to normal in the post-Gaddafi era.