Sergeant Alexander Blackman, who served in the 42 Commando, was jailed for life after being convicted of murdering the captive in Afghanistan’s Helmand province in 2011.
The never-before-seen video shows the moments before the killing and was released ahead of Sgt Blackman’s appeal against the conviction next week.
In the clip, captured from a helmet-mounted video camera worn by one of the junior Marines in Sgt Blackman’s patrol, a number of soldiers can be seen standing in a grassy field.
The footage has been released for the first time
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They had been sent to counter two insurgents who had been spotted creeping up on a remote British outpost.
An Apache helicopter was also dispatched to assist in the search for the Taliban fighters.
As the aircraft approaches, loud gunfire can be heard from the aircraft as it unleashes from its 30mm cannon.
The footage was captured on a helmet camera in Helmand
Distanced away from the carnage, the Marines can be heard shouting: “I think he is dead” as the sound of gunfire continues.
As the battleground falls silent, a voice says: “They’ve missed him. They’ve f***ing missed the cheeser.”
Another clip shows Sgt Blackman and Marine C, Jack Hammond, walking over to examine a wounded man.
The video shows the moments leading up to the killing of the insurgent
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The soldiers approach the insurgent, who can not be seen in the footage, to discover an AK47, spare ammo and a hand grenade by his body.
Although the video does not show the killing itself, it was documented in court that the helmet-mounted camera showed Sgt Blackman quoting Shakespeare before shooting dead the insurgent with a 9mm pistol at close range.
The footage was not released at the time over fears it may be used by terrorists as propaganda.
Claire Blackman, the wife of Alexander Blackman, speaks after his bail was refused last year
However, three of the UK’s most senior judges gave permission for its partial release on Tuesday after national newspapers and broadcasters argued it should be made public.
Before now, only pictures and audio had been published.
Sgt Blackman’s appeal is due to being on Tuesday after a Criminal Cases Review Commission found there was a “real possibility” his conviction could be overturned.
It has been scheduled to last three days at the Royal Courts of Justice in London.
Rally in support of Alexander Blackman by servicemen and ex-servicemen in Westminster in October
The decision to grant the appeal was made after new evidence emerged relating to his mental health at the time of the killing in September 2014 – and because an alternative verdict of unlawful act manslaughter was not available during his trial.
The Court Martial Appeal Court will decide whether his conviction will be reduced to manslaughter, by way of diminished responsibility.
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