AN AUTHOR and former Royal Marine has defended the actions of a comrade serving a life sentence for killing an injured Afghan fighter.

Scottish journalist Neal Ascherson said he killed two wounded enemies to “put them out of their misery”.

Mr Ascherson, 84, from London, revealed that he killed the “hideously wounded” guerrillas during the Malayan Emergency in 1952 as he gave his support to a campaign to free Sergeant Alexander Blackman, who is originally from Brighton.

Blackman, 42, who served in the same Plymouth-based 42 Commando as Mr Ascherson, was convicted of murdering a captive in Afghanistan’s Helmand province during the conflict in 2011.

Mr Ascherson told a national newspaper: “The wrong of taking a life doesn’t diminish. Instead it separates from all the justifications, however valid.

“Did he shoot out of pity, or out of frantic loss of control, or to make sure that his squad made it back across a killing ground without the burden of a wounded prisoner?

“Whichever his motive, Blackman’s act was ‘culpable homicide’ – manslaughter.”

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.

The writer 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.”

Mr Ascherson believes Blackman’s conviction was a “miscarriage of justice” and said he will continue to support the campaign to free him.

Blackman, who was known as Marine A during his trial, denied murder but was convicted in November 2013 by a court martial in Bulford, Wiltshire.

He claimed that he thought the mortally wounded insurgent was already dead when he fired.

He won the right to appeal last December, following the presentation of new evidence regarding his mental health at the time and as there was no manslaughter verdict available.

Thousands of people have signed a petition to support Blackman, who will appeal against the verdict at the Court Martial Appeal Court.