"It's been confirmed that al Qaeda's number two, Atiyah abd al-Rahman, was killed earlier this week in Waziristan, Pakistan," a senior US Administration official said.
"Atiyah's death is a tremendous loss for al-Qaeda because Ayman al-Zawahiri (al-Qaeda's chief) was relying heavily on him to help guide and run the organisation, especially since bin Laden's death," the official said.
He said the trove of materials from bin Laden's compound showed clearly that Atiyah was deeply involved in directing al-Qaeda's operations even before the raid.
The official said that Atiyah played multiple roles within the organisation and will be very difficult to be replaced.
However, it was immediately not known how Atiyah was killed.
This is the first major catch after the May 2 operation in which US commandos killed bin Laden in a safe house in Pakistan's garrison city of Abbottabad.