Members of the bin Laden family, interviewed by The Guardian in a story published Thursday, said Hamza bin Laden is somewhere in Afghanistan -- and they believe he's fighting U.S. and coalition forces there to avenge his father.
"The people at university changed him," mother Alia Ghanem said of her son being an economics student at King Abdulaziz University in Saudi Arabia. "He became a different man. He was a very good child until he met some people who pretty much brainwashed him in his early 20s. You can call it a cult. They got money for their cause.
"I would always tell him to stay away from them, and he would never admit to me what he was doing, because he loved me so much."
After notoriously eluding U.S. forces for nearly a decade after the Sept. 11 attacks, bin Laden was killed by Navy SEALs in a raid on his Pakistan hideout seven years ago. Hamza bin Laden, 29, has been designated a terrorist by the United States government.
The family believes he is Osama bin Laden's youngest son, and said they are surprised by his apparent endorsement of terrorism.
"We thought everyone was over this. Then the next thing I knew, Hamza was saying, 'I am going to avenge my father,'" uncle Hassan bin Laden said. "I don't want to go through that again.
"If Hamza was in front of me now, I would tell him: 'God guide you. Think twice about what you are doing. Don't retake the steps of your father. You are entering horrible parts of your soul.'"
Hamza bin Laden first appeared involved with terrorism in 2005 and he was implicated in the assassination of former Pakistani Prime Minister Benazir Bhutto two years later. In an audio message in 2015, he called on militants to wage jihad against the United States, Britain, France and Israel.
The bin Laden family resides in Jeddah, Saudi Arabia, and remains prominent in society there. Saudi officials believe their speaking out will cast Osama bin Laden as a rogue operator -- rather than a Saudi agent -- behind the 2001 attacks.
Fifteen of the 19 hijackers were Saudis and some have suggested they received government support.