Osama bin Laden's son-in-law

Abu Ghaith became an international name after the 9/11 attacks in 2001, when he appeared on pan-Arab satellite television urging Muslims everywhere to fight the United States and warning of more attacks to come.

A teacher and mosque preacher in Kuwait, he was stripped of his Kuwaiti citizenship after 9/11.

Mr King said Abu Ghaith was involved in the planning in those attacks, and Tom Lynch, a research fellow at Washington's National Defence University, described Abu Ghaith as one of a small handful of senior al Qaida leaders "capable of getting the old band back together and postured for a round of real serious international terror."

"His capture and extradition not only allows the US to hold, and perhaps try, a reputed al Qaida core survivor, further tarnishing the AQ (al Qaida) core brand, but it also points to the dangers for those few remaining al Qaida core refugees," Lynch said.