Seoul: South Korea's constitutional court on Thursday ruled that a special counsel investigation into fraud allegations against President Lee Myung-bak could go ahead.

The government in December approved the special counsel, making Lee the first South Korean president-elect to face a criminal investigation.

Lee won a landslide victory in the December 19 presidential election with pledges to revive the economy.

Lee's relatives had requested the court to review the planned probe, saying some of the investigation process was unconstitutional.

If the court agrees, the probe into allegations that Lee was linked to an investment firm suspected of defrauding investors of millions of dollars may have to be dropped.