Image copyright PA Image caption Sgt Alexander Blackman had his murder conviction reduced to manslaughter

The Royal Marine jailed for shooting dead a wounded Taliban fighter has been released from prison.

Sgt Alexander Blackman received a life term in 2013 for murder, but his conviction was reduced to manslaughter.

The 42-year-old from Taunton, Somerset, served more than three years of a seven-year sentence.

Judges at the Court Martial Appeal Court were told he had a recognised mental illness at the time of the killing in September 2011.

Blackman - who was known as Marine A during the original trial process and fully identified when he was convicted - was serving his sentence at Erlestoke Prison, near Devizes, Wiltshire. He was released at 00:18 BST.

His original murder conviction was quashed in March.

The appeal hearing came after his wife Claire led a campaign alongside author Frederick Forsyth and the Daily Mail newspaper.

Blackman had more than 13 years of service and had previously been deployed to Iraq on three occasions and to Afghanistan in 2007.

The Royal Marine's barrister, Jonathan Goldberg, said he had been approached about making a film about Blackman's story.

"The case is controversial - this is obviously why Hollywood want to make a film about it," he said.

"I was there last week meeting some important people, and the idea is that Kate Winslet might be cast as Claire, Tom Hardy as Al and - can you believe it - Al Pacino as me."

Media playback is unsupported on your device Media caption Sgt Blackman was driven away from prison in the early hours of Friday

His supporters had hoped the quashing of the murder conviction would lead to his reinstatement in the Royal Marines.

However, the judges at the appeal hearing said his dismissal from the service should remain.

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The killing on 15 September 2011 took place during the final month of 42 Commando's six-month tour of duty to Helmand province - a deployment which saw the unit lose seven men.

Footage from an unofficial helmet-mounted camera of another marine was found during an unrelated investigation and showed Blackman shooting the Afghan prisoner in the chest at close range with a 9mm pistol.

The shooting took place after a British patrol base came under fire. One of two insurgents was seriously injured by gunfire from an Apache helicopter sent to provide air support, and the marines from 42 Commando found him in a field.

Image caption Sgt Blackman's actions were caught on another marine's helmet camera

In their sentencing remarks, the judges said that although Blackman's responsibility was diminished, he "still retained a substantial responsibility for the deliberate killing".

They said other "aggravating factors" included the vulnerability of the insurgent, who could not defend himself, and "the decision to ensure that the killing was not witnessed by the overhead helicopter and thereafter to cover up the evidence of what had happened".

Two other marines from 42 Commando were tried alongside Blackman in 2013 but acquitted.

Blackman lost an appeal against his conviction in May of the following year, but his 10-year minimum term was reduced to eight years.

The Criminal Cases Review Commission later granted him a fresh appeal after his lawyers submitted expert evidence relating to his mental state at the time of the offence.