The brother of a Jordanian pilot burned alive in Syria by the Islamic State has revealed that he pleaded for the air force to bomb the house where his captive sibling was being held to spare him from a horrific death at the hands of the terror group.

The brutal killing took place sometime in late 2014 or early 2015 and sparked outrage internationally.

Osama Krayem, a 32-year-old Swede already serving long prison sentences for his role in the Paris and Brussels attacks in 2015 and 2016, is on trial in Stockholm suspected of war crimes and terrorist crimes for his role in the pilot's killing.

On December 24, 2014, an aircraft belonging to the Royal Jordanian Air Force crashed in Syria.

The pilot, Maaz al-Kassasbeh, was captured the same day by ISIS fighters near the central city of Raqqa and was burned alive in a cage sometime before February 3, 2015, when a video of the gruesome killing was published, according to the prosecution.