OSAMA bin Laden’s 12-year-old grandson has reportedly been killed in an air strike.

His father, Hamza Bin Laden, revealed he died on the Afghanistan-Pakistan border last year.

The young boy, also named Osama, was praised for his “martyrdom”.

According to the Hindustan Times, a leaked letter from Osama’s father titled “Letter From Sheikh Mujahid Hamza Bin Laden” was published by al-Qaeda’s propaganda outlet, Global Islamic Media Front.

The letter reportedly contains a picture of the dead boy and read: “We console ourselves and you on the martyrdom on the hero cub ... the grandson of braver ... our son Osama, may Allah have mercy on him.”

It also referred to him acting out scenes of martyrdom with other children.

The boy’s father, Hamza, has been named as the heir to the evil empire founded by Osama bin Laden, who was shot dead by US forces in Pakistan in 2011.

The news comes after more details about the dead terrorist leader were released by the CIA last year.

bin Laden had children’s cartoons, Hollywood movies and documentaries about himself on a computer seized after the September 11 mastermind was killed in 2011.

The CIA released a vast archive of intimate Al-Qaeda documents, including bin Laden’s handwritten diary, seized in the deadly 2011 raid on his Pakistani compound.

The huge trove includes images of diary pages left by the Saudi-born global extremist leader and a wedding video that includes the first public images of his son Hamza as an adult.

Controversially, scholars from a Washington think-tank who were given access to the now declassified trove say the documents also shed new light on Al-Qaeda’s murky relationship with Iran.

“Today’s release ... provides the opportunity for the American people to gain further insights into the plans and workings of this terrorist organisation,” said CIA director Mike Pompeo.

The CIA put online 470,000 additional files seized in May 2011 when US Navy SEALs burst into the Abbottabad compound and shot dead the leader of Al-Qaeda’s global extremist network.

Reuters reports it is the fourth tranche of materials taken from the walled compound where bin Laden and his family lived to be made public by the US government since May 2015.

Materials that still have not been released are being withheld because they could harm national security, are blank, corrupted or duplicate files, are pornographic or are protected by copyright, said a CIA statement.

The copyright-protected materials include more than two dozen videos such as Antz, Cars and other animated films, the role-playing game Final Fantasy VII and Where in the World is Osama bin Laden and two other documentaries about the al Qaeda leader, the CIA said.

The Washington Post reports that his collection also included Chicken Little, as well as BBC and National Geographic documentaries, including World’s Worst Venom and Inside the Green Berets.

He also read books by Noam Chomsky and Bob Woodward and watched porn.

According to Thomas Joscelyn and Bill Roggio, scholars from the Foundation for Defense of Democracies who were allowed to see the trove before it was made public, it provides new insights.

“These documents will go a long way to help fill in some of the blanks we still have about al-Qaeda’s leadership,” Roggio said.

The inclusion of Hamza bin Laden’s wedding video, for example, gives the world public the first image of bin Laden’s favourite son as an adult — an image apparently shot in Iran.

Previous document releases, including letters revealed by AFP in May 2015, show that bin Laden was grooming Hamza to succeed him as leader of Al-Qaeda’s global jihadist campaign.

But plans for him to come to bin Laden’s Abbottabad hide-out seem to have been abandoned after the deadly US raid, and the young man — now aged 27 or 28 — is presumed to be in Iran.