Omar Bakri Muhammad, another former al-Muhajiroun leader and radical Muslim preacher, said Adebolajo attended his London lectures in the early 2000s. Muhammad fled London and resettled in Lebanon in 2005 after suicide attacks on London's public transit system killed 56 people, including four bombers.
Police have not officially named the two suspects. The AP has received confirmation of their identities from British officials speaking on condition of anonymity because they are not authorized to disclose the information.
Few details have emerged about Adebowale besides one reported brush with death as a teenager.
The Guardian reported Saturday that Adebowale was stabbed in 2008, when a man attacked him and two friends in a London apartment. One 18-year-old friend died and the attacker received a life sentence for murder, the newspaper said.
MI5 Director-General Andrew Parker is expected to deliver a preliminary report next week to Parliament's Intelligence and Security Committee detailing what the agency knew about both suspects and whether MI5 could have done anything to stop the attack.
The directors of Britain's foreign spy agency, MI6, and Britain's eavesdropping agency, GCHQ, also are expected to give reports on what intelligence they had on the two men.