One of the boys shown murdering prisoners in Islamic State’s new propaganda video is British, the terror group alleges.

The footage shows five boys dressed in camouflage standing behind a row of kneeling prisoners in orange jumpsuits. After one boy makes a statement in Arabic the others raise their guns before shooting the prisoners, who are referred to in the video only as “atheist Kurds”, dead.

The white child in the video is captioned as being called Abu Abdullah al-Britani, indicating that he is British. The name “al-Britani” (the Briton) has been taken on by many of the jihadists who left Britain to fight with Islamic State in Iraq and Syria.

The other boys are captioned as al-Masri (the Egyptian), al-Tunisi (the Tunisian), al-Kurdi (the Kurd) and al-Uzbaki (the Uzbek).

During the video, the youth identified as a Tunisian announces to the camera: “To the atheist Kurds, what is between me and you are days during which the hair of young children turns grey. The war with you has yet to begin. Neither America, France, Britain, nor Germany will benefit you,” according to Site Intelligence Group.

The video also shows footage of elderly men killing Syrian soldiers, and men from rival Islamic groups being beheaded.

The identity of the boy labeled al-Britani remains unclear, and the foreign office has yet to comment. The footage is thought to have been filmed in Raqqa, Syria, Islamic State’s self-declared “capital”.

Anti-terror police were last night looking into whether the white child is Muslim convert Sally Jones’ son, the Mirror reported. Jones, originally from Kent, left for Syria with her 10 year old son in 2013 in order to marry notorious jihadi Junaid Hussain.

In February Islamic State released a video which appeared to show four year old Isa Dare pressing a button to blow up a car, killing three prisoners inside it. Son of Lewisham-born jihadi bride Grace “Khadija” Dare, the child announces that jihadists “will kill the kuffar” (unbelievers).