A law enforcement official says investigators are conducting a probe into who leaked information about an al-Qaida plot in which an explosive device was to have been detonated on a U.S.-bound airline flight.

The official spoke on condition of anonymity about the ongoing leak investigation, which is just getting under way.

The probe follows stories by The Associated Press and other news organizations disclosing the terrorist operation by the group known as al-Qaida in the Arabian Peninsula. The reports said that al-Qaida had completed a sophisticated new, nonmetallic underwear bomb last month and that the would-be suicide bomber actually was a double agent working with the CIA and Saudi intelligence agencies.