Personal letters seized in the raid that killed former Al Qaeda leader Osama bin Laden revealed that his son wants to carry on his murderous ideology and is bent on "avenging his dad's death", according to a former FBI agent.
"That son today is poised to lead a stronger, larger Al Qaeda," Ali Soufan, who was leading the Federal Bureau of Investigation's probe of the terror group after the 11 September, 2001, attacks, told CBS News in an interview.
Soufan described a letter from the son, Hamza, that was collected in the raid and now declassified.
"He tells Osama (in the letter) that he remembers 'every look... every smile you gave me, every word you told me'".
Hamza would be about 28 now and wrote the letter when he was 22 and had not seen his father in several years.
Hamza also wrote this: "I consider myself to be forged in steel. The path of 'jihad' for the sake of God is what we live."
Hamza's potential as a leader was recognised years ago when he was still a boy, says Soufan.
The child was used in propaganda videos, sometimes holding a gun.
"He was a poster kid for the Al Qaeda, and for members of Al Qaeda, who were indoctrinated with these propaganda videos, he means a lot to them," Soufan told CBS News.
The US has named Hamza a "specially designated global terrorist" -- the same classification his father once held.
"He even sounds like his father," says Soufan.
"His recent message that came out, he delivered the speech as if it's his father...using sentences, terminology that was used by Osama bin Laden."
Hamza has recorded four audio messages in the last two years.
Soufan believes Hamza can inspire and unite the jihadi movement, adding "Al Qaeda is stronger than ever. I don't believe even bin Laden in his wildest dreams thought that he will have followers who command armies, troops, lands."
Osama Bin Laden was killed in Abbottabad, Pakistan, on 2 May, 2011, by US Navy SEAL Team Six.
Following his death, dozens of letters written by him to his family and senior members of Al Qaeda were released.