WASHINGTON - The would-be suicide bomber deployed by an al-Qaida affiliate to blow up a US-bound airliner is a double agent, reports indicated Tuesday evening.

The New York Times and CNN reported that the bomber was actually an intelligence agent for Saudi Arabia who infiltrated the Yemen branch of the terrorist group and volunteered for the suicide mission.

Citing unnamed US officials, the reports said that after receiving the device, the double agent left Yemen, and delivered both the bomb designed for his attack and information on leaders of the al-Qaida in the Arabian Peninsula, or AQAP, to Saudi, US and other foreign intelligence agencies.

The agent provided "critical information that permitted the CIA to direct the drone strike on Sunday that killed Fahd Mohammed Ahmed al-Quso, the group's external operations director and a suspect in the bombing of the American destroyer Cole in Yemen in 2000," the New York Times reported.

The bomb, designed by the group's top explosives expert to be invisible to airport security, is at the hands of the FBI, which is analyzing its properties.

Officials said the agent, whose identity they would not disclose, is now safe in Saudi Arabia.

US counter-terrorism officials said intelligence agencies foiled an attempt by AQAP to destroy a US-bound airliner one year after the killing of Osama bin Laden, several major US media network including CNN reported on Monday.

The plot involved an upgrade of the underwear bomb that failed to detonate aboard a jetliner over Detroit on Christmas 2009. This new bomb was also designed to be used in a passenger's underwear, but contained a more refined detonation system, US officials said.