Hamza bin Laden is claimed to have died in the secret hit job by the US government and intelligence agencies are braced for a retaliation.
The Sunday Mirror has been told by security sources there have been warnings of an al-Qaeda resurgence and spectacular attacks.
One western intelligence analyst said: “There is a strong will still out there for another 9/11 so the bin Laden nightmare is far from over – even though it is likely the founder’s only possible terrorist heir has been killed.
“Operationally, Hamza was inexperienced but as a scion of the most famous terror mastermind the world has known, he was irresistible.”
“Osama bin Laden knew his son’s true value and hoped that one day Hamza would take up the challenge of leading al-Qaeda so he could not be allowed by the west to rally support for a new and more dangerous al-Qaeda.”
Hamza was reportedly present when his killer dad plotted 9/11.
Nearly 3,000 people were killed in hijacked plane attacks on the World Trade Centre’s twin towers in New York and on the Pentagon in Washington DC.
The father and son also spent time together as they fled to Pakistan during the US invasion of Afghanistan.
It comes as the United Nation warns a huge 30,000 strong army of Isis fighters may still be alive and are bent on revenge after the collapse of their so-called Caliphate in Syria and Iraq.
A report said: “Their future prospects will be of international concern for the foreseeable future.
“Some may join al-Qaeda or other terrorist brands that may emerge. Some will become leaders or radicalisers.”
The report is based on information supplied by intelligence agencies of UN member states, and offers a glimpse into security services fears around the world.