ISIS supporters are warning the ‘hugest video yet’ will soon be released by the media arm responsible for some of the most disturbing ISIS propaganda videos to emerge from the group to date.

Charlie Winter, a researcher for the counter extremism think-tank Quilliam, said rumours among ISIS supporters that the Mu'assasat al-Furqan media centre will release a video are rife on social media.

Al-Furqan has distributed a host of violent images and videos depicting atrocities condemned by human rights groups as war crimes online, including the execution of a Jordanian pilot, who was burned alive in a cage by the extremist group.

Mr Winter told The Independent: “Arab ISIS supporters are really gunning for this video – they have been saying it is not for the faint-hearted, or “forbidden”.

“It’s being described as the ‘hugest’ of all releases from al-Furqan, which is the media outlet that has produced the most horrific footage to date.”

Mr Winter said he initially saw Western ISIS supporters discussing it on social media. Now, rumours are being circulated by the accounts of Arab ISIS supporters.

"The initial sources for this rumour are not the ones who usually release the information – so there is a chance it might not be true.

That said, there has been continued chatter on the usual channels about the release for many hours now,” he added.

A previous ‘Clanging of the Swords’ video purported to show hostages digging their own graves and the massacre of Iraqi soldiers in Tikrit.

“The content of those videos is an orgy of violence interspersed with occasional evidence of social work,” Mr Winter said.

“It’s particularly shocking how Isis supporters are so desperately keen for a repeat of it.”