Umar Farouk Abdulmutallab, seen in this undated photo, was known to U.S. officials, who say their information was not specific or credible enough to put his name on a no-fly list. (Associated Press)

The name of the Nigerian accused of trying to blow up a Christmas Day transatlantic flight had been in one of the U.S. government's many terror databases since November, when his father alerted embassy officials in Nigeria about his son's beliefs.

However, Umar Farouk Abdulmutallab came to the attention of intelligence officials months before that, according to a U.S. government official involved in the investigation. The official spoke on condition of anonymity because it is ongoing.

Still, none of the information the government had on Abdulmutallab rose to the level of putting him on the official terror watch list or no-fly list.

On Christmas Eve, the 23-year-old — who later claimed to law enforcement that he was operating on orders from al-Qaeda — was able to carry a concealed explosive device onto a U.S.-bound airplane.

Officials warn it is still early in the investigation. But U.S. politicians are already calling for hearings, and the government may order a review.

President Barack Obama has been receiving regular updates on the investigation from his staff, and his national security and policy aides have been asking whether the policies the U.S. has in place are working.

These internal discussions marked the informal start to what will likely become a formal executive branch inquiry into an attack that failed because the bomb did not go off as planned — not because the security-intelligence complex stopped it.

Officials allege syringe found on suspect

Law enforcement officials are making the following allegations about events around the Christmas Day attack on Northwest Flight 253, based on passenger accounts:

• On Dec. 24, Abdulmutallab travelled from Nigeria to Amsterdam and then on to Detroit with an explosive device attached to his body.
• Part of the device contained PETN, or pentaerythritol tetranitrate, and was hidden in a condom or condom-like bag just below Abdulmutallab's torso. PETN is in the same chemical family as nitroglycerine.
• PETN is also the same material convicted "shoe bomber" Richard Reid used when he tried to destroy a trans-Atlantic flight in 2001 with explosives hidden in his shoes. Abdulmutallab also had a syringe filled with liquid.
• As the plane approached Detroit, Abdulmutallab went to the bathroom for 20 minutes. When he returned to his seat, he complained of an upset stomach and covered himself with a blanket.
• Passengers heard a popping noise, similar to a firecracker. They smelled an odour, and some passengers saw Abdulmutallab's pant leg and the wall of the airplane on fire.
• Three passengers and a crew member quelled the flames with blankets and fire extinguishers, and restrained Abdulmutallab who later told a flight attendant he had an "explosive device" in his pocket. He was seen holding a partially melted syringe.

The aircraft landed in Detroit shortly after the incident.

On Saturday, federal officials charged the young man with trying to destroy the airplane. A conviction on the charge could bring Abdulmutallab up to 20 years in prison and a $250,000 US fine.

U.S. District Judge Paul Borman read Abdulmutallab the charges in a conference room at the University of Michigan Medical Center in Ann Arbor, Mich., where the former London university student is undergoing burn treatment.

Abdulmutallab smiled as he was wheeled into the room, his left thumb and right wrist bandaged and part of the skin on the thumb burned off.

Abdulmutallab claimed to have received training and instructions from al-Qaeda operatives in Yemen, law enforcement officials said. He is also believed to have had internet contact with Islamist radicals.

While intelligence officials said Saturday that they are taking seriously Abdulmutallab's claims that the plot originated with al-Qaeda's network inside Yemen, several added that they had yet to see independent confirmation. The officials spoke on condition of anonymity because the investigation is incomplete.

Father concerned about religious beliefs

Four weeks ago, Abdulmutallab's father told the U.S. embassy in Abuja, Nigeria, that he was concerned about his son's religious beliefs. This information was passed on to U.S. intelligence officials.

Abdulmutallab received a valid U.S. visa in June 2008 that is good through 2010.

His is one of about 550,000 names in the Terrorist Identities Datamart Environment database, known as TIDE, which is maintained by the U.S. National Counterterrorism Center and was created in response to the Sept. 11, 2001, attacks.

Homeland Security Secretary Janet Napolitano, appearing on ABC's This Week on Sunday, said investigators did not have enough credible information to move the suspect to the U.S. no-fly list, containing the names of people deemed to be a threat to the security of aircraft or air travellers.

She said there is no indication that the suspect is part of a larger terrorist plot. Napolitano refused to say whether Abdulmutallab has a connection to al-Qaeda, citing the ongoing criminal investigation.

She confirmed that there was no air marshal on the plane with Abdulmutallab.