Osama Bin Laden's Son And Heir Is Dead, U.S. Officials Say

American authorities have intelligence that Hamza Bin Laden, the son of 9/11 terror mastermind and al-Qaeda leader Osama, has died.

NBC first reported the news on Thursday, quoting three unnamed officials who said Hamza -- who had been developing into a leadership role with al-Qaeda -- was dead. It is not known when or how he died, but authorities are confident that he is deceased.

The U.S. government is expected to make an announcement on Thursday morning (AEST) on the matter. Asked earlier if he had intelligence that Hamza was dead, American President Donald Trump told reporters: "I don't want to comment on it."

Hamza bin Laden, the son of late al-Qaeda leader Osama bin Laden. Photo: AAP

Hamza is believed to have been born around 1989 in Saudi Arabia, and lived with his father in Afghanistan. He was not in the Pakistan compound where Osama was found and killed in 2011, but documents in the property were said to reveal that Hamza was being groomed for al-Qaeda leadership.

Hamza was thought to be under house arrest in Iran at the time, and documents recovered from the compound indicated that aides had been trying to reunite him with his father.

His last public comments were released in 2018. In 2015, he called for attacks on the United States; in 2017 issued a call for a jihad in Syria, and urged disparate radical groups to unify under an al-Qaeda banner.

Osama Bin Laden, in a video from 1998 at a news conference in Khost, Afghanistan. Photo: AAP

In February this year, the American government announced a US$1 million reward for information on Hamza's whereabouts.

"Investigators believe Hamza bin Laden is married to the daughter of Al Qaeda senior leader Abdullah Ahmed Abdullah, aka Abu Muhammad al Masri, who has been indicted for his alleged involvement in the August 7, 1998, bombings of the United States Embassies in Tanzania and Kenya," the FBI states on its Most Wanted website.

"Hamza bin Laden is wanted for questioning in connection with his membership in the Al Qaeda organisation and his public declarations threatening the security of the United States."

Hamza Bin Laden. Photo: FBI

Introduced by al-Qaeda's chief Ayman al-Zawahiri in an audio message in 2015, Hamza provides a younger voice for the group whose ageing leaders have struggled to inspire militants around the world galvanised by Islamic State, analysts say.

Hamza has called for acts of terrorism in Western capitals and threatened to take revenge against the US for his father's killing, the US State Department said in 2017 when it designated him as a global terrorist.

The 9/11 attack in New York, masterminded by Osama Bin Laden. Photo: AAP

He also threatened to target Americans abroad and urged Saudi tribes to unite with Yemen's Al-Qaeda in the Arabian Peninsula to fight against Saudi Arabia, it said.

In March, Saudi Arabia announced it had stripped Hamza bin Laden of his citizenship, saying the decision was made by a royal order in November 2018.

More to come.

With AAP.