The suspect carried enough explosive material to blow a large hole in the plane had it been detonated, CNN quoted an unidentified source with knowledge of the investigation, as saying.
The Obama administration is investigating whether al-Qaeda was involved in the attempted attack, The Telegraph reports.
Abdulmutallab suspected of plotting to blow up the plane, has been moved to prison from a hospital and was not expected to appear at a court hearing in Detroit, where prosecutors plan to seek an order to obtain his DNA.
23-year-old Abdulmutallab is charged with attempting to blow up the Northwest Airlines jumbo as it approached Detroit on a flight from Amsterdam with almost 300 people on board.
Asked whether al-Qaeda was involved, Homeland Security Secretary Janet Napolitano told ABC's "This Week" programme, "That is now the subject of investigation and it would be inappropriate for me to say and inappropriate to speculate. Right now, we have no indication that it is part of anything larger."
On Friday, Dec 25, passengers and crew overpowered Abdulmutallab after he set alight an explosive device attached to his body.