The clip, taken in Helmand Province in September 2011, was captured by a camera mounted on the helmet of one of the commandos.
During the recording, which lasts for 6min 24sec, a single gunshot can be heard, followed by groans from the insurgent, an unknown Afghan national.
Three soldiers, known only as Marines A, B and C have been charged with murdering the man, who was lying in a field seriously injured after an Apache helicopter attack.
After the shot is fired, Marine A can be heard telling the man: “There you are. Shuffle off this mortal coil you ****. It’s nothing you wouldn’t do to us.”
A panel at a court martial in Bulford, Wiltshire, yesterday retired to consider its verdicts in the case, after two weeks of
Judge Advocate General Jeff Blackett has ruled graphic video footage – from which the audio recording was taken – must not be released.
“Its release may be for proper journalistic purposes … but would also be used for sensationalist purposes by others and propaganda purposes by terrorist groups,” he said.
“More importantly its release will increase the threat of harm to British service personnel,” he said.
“I am not prepared to make an order which may lead to the injury or death of a single member of the British armed forces and in making this decision I have erred on the side of safety.”
However, Judge Blackett permitted the release of certain still images from the video, which was captured on a camera worn by Marine B.
The video footage shows the Royal Marine patrol standing waiting outside a field of tall crops, with an Apache helicopter audible overhead.
Servicemen can be heard swearing and complaining about their task of carrying out a “battle damage assessment” after the Apache attack.
During the trial, the court martial heard the insurgent had been shot at with 139 30mm anti-tank rounds but was still alive – albeit seriously injured – when discovered by the patrol.
One commando can be heard asking: “Why didn’t they use a f***ing rocket?”. Another replies: “F*** me, it’s just error after error after error.”
Marines A and C are seen scouting out the field, locating the Afghan before calling the others over.
As Marine B walks towards them, the camera captures its first shot of the seriously injured insurgent, lying on the ground, wearing a white dish-dash and covered in blood.
The patrol drags the man across the field and into a wooded area nearby, throwing him to the ground.
Marine A is heard asking “Anybody want to do first aid on this idiot?”
Marine B is heard to loudly reply “No”. Marine C offers to shoot the man in the head, which is refused as Marine A rules “that would be f***ing obvious”.
The injured man, whose shirt had been pulled up his bloodied back, suffers kicks from the servicemen, who then flip him from back to front.
Marine A is seen walking forward, bending down, and shooting the man at close range in the centre of his chest with a 9mm pistol.
Giving evidence to the court martial, Marine A insisted he believed the insurgent was dead at the time and he was simply shooting into a corpse in anger.
After shooting the man, Marine A is seen turning to the other members of the patrol and telling them: “Obviously this doesn’t go anywhere, fellas.
“I just broke the Geneva Convention.”