A former Royal Marine has come to the defence of a comrade imprisoned for killing an injured Afghan fighter, and told how he fatally shot two wounded enemies to "put them out of their misery".
Neal Ascherson, 84, revealed that he killed the "hideously wounded" guerrillas during the Malayan Emergency in 1952, as he lent his support to a campaign to free Sergeant Alexander Blackman, also known as Marine A.
Blackman, who served in the same Plymouth-based 42 Commando as Mr Ascherson, is serving a life sentence after being convicted of murdering the captive in Afghanistan's Helmand province in 2011.
Thousands of people signed a petition to support Blackman, 42, who is preparing to appeal against his conviction and sentence at the Courts Martial Appeal Court.
Mr Ascherson, who became a journalist after leaving the Marines, said he was a 19-year-old officer when a sub-section he was leading gunned down a patrol of guerrillas who walked into their ambush.
Writing in The Times, he said: "I went forward and found two men hideously wounded, unconscious but still just moving.
"I don't remember a moment's hesitation or doubt about what to do: I pointed my carbine and put them both out of their misery.
"Through the gun-deaf whistling in my ears, I heard a Marine say, 'You wouldn't leave a dog like that'. Still less two young men."
Mr Ascherson said the killings had haunted him in later life but he still feels they were justified.
He said: "Nobody said a word about it later, but I know now that this was legally murder.
"'Mercy killing' isn't a category recognised by military law, although soldiers have always done it and - I don't doubt - still do almost daily in wars across the world."
Blackman shot the injured insurgent in the chest and told him: "There you are. Shuffle off this mortal coil, you c***. It's nothing you wouldn't do to us.''
He denied murder but was convicted in November 2013 by a court martial in Bulford, Wiltshire, and sentenced to life with a minimum term of 10 years.
Mr Ascherson said: "Whichever his motive, Sergeant Blackman's act was 'culpable homicide' - manslaughter - and to call it murder is a tragic failure of justice."
Blackman, of Taunton, Somerset, won the right to appeal in December following the presentation of new evidence regarding his mental health at the time and because an alternative verdict of unlawful act manslaughter was not available in the trial.