Osama bin Laden's son has vowed revenge on the west for killing his father and is set to become the next leader of al-Qaeda, a former FBI agent has warned.
Ali Soufan, who was the FBI's lead investigator of al-Qaeda after the 9/11 terror attacks, examined documents seized from bin Laden's Pakistan compound when he was killed by US Navy Seals in 2011.
"I consider myself... to be forged in steel," Hamza bin Laden, now thought to be around 28 wrote. "The path of jihad for the sake of God is what we live."
Bin Laden hoped his son Hamza would eventually succeed him
Mr Soufan told CBS News about a letter Hamza wrote his father, who he had not seen in several years.
He said: "He tells him that… 'I remember every look… every smile you gave me, every word you told me.'"
Hamza was 22-years-old when the letter was written and his leadership potential had been recognised when he was a boy.
The Bin Laden Tapes
When he was still a child, he used to appear in propaganda videos holding a gun, the former FBI agent said.