Media playback is unsupported on your device Media caption Wife of Marine A Claire Blackman tells Today if her husband could 'undo his actions he would do in a heartbeat'

Royal Marine Alexander Blackman has "always regretted his actions" in shooting dead a wounded Taliban fighter in Afghanistan, his wife has said.

Claire Blackman, of Taunton, Somerset, told the BBC that if her husband could turn back the clock and change events of 2011, "he would do in a heartbeat".

The marine's sentence has been cut to seven years after his murder conviction was reduced to manslaughter.

From jail, he told the Daily Mail he felt a "profound sense of relief".

It is likely he will be released soon because he has already served three-and-a-half years in jail.

Blackman, 42, who was initially known as Marine A in court proceedings, was convicted of murder in November 2013.

Earlier this month, his conviction was reduced to manslaughter on the basis of diminished responsibility. His sentence was cut on Tuesday.

His wife told BBC Radio 4's Today programme she felt "huge relief and delight".

She added: "He's always regretted his actions. If he could turn the clock back and undo that moment, he would do in a heartbeat.

Lessons to learn

"He has never denied that his actions on that day were caused by a serious lack of judgement, which we now know to be due to a combat stress disorder."

She said there were "huge lessons" to learn from the case - from the court martial process to the way servicemen and women are supported in "particularly stressful circumstances".

"I feel my husband had very little support out on the ground and that was certainly something that was discussed at length by the courts," she said.

She said she had received support from the public, friends and service colleagues in her campaign to have Blackman freed, but there had been no engagement with the Royal Marines at a formal, senior level.

Media playback is unsupported on your device Media caption Claire Blackman speaking outside court

Blackman watched Tuesday's hearing at the Court Martial Appeal Court in London via a video link from jail.

He told the Daily Mail, which led the campaign for his release, he had been "braced for the worst".

"My heart sank when the judge started talking about my current sentence being the equivalent of 16 years, and I thought it was somehow leading to a larger sentence," he said.

"I just felt a profound sense of relief when they said seven [years]."

Media playback is unsupported on your device Media caption Extract from helmet camera audio recording of incident in Helmand

He added he was "an extremely lucky man to have Claire as a wife".

"We hear so many other stories of relationships going bad when you are inside.

"That hasn't happened for us. Her love and support has simply sustained me."

Blackman's dismissal from the military remains, although it is no longer classed as dishonourable.

The case relates to an incident in September 2011 when one of two insurgents was seriously injured by gunfire from an Apache helicopter and marines from 42 Commando found him in a field.

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.

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

The court martial heard that Blackman used abusive language and said: "There you are. Shuffle off this mortal coil."

He then turned to his comrades and said: "Obviously this doesn't go anywhere, fellas. I just broke the Geneva Convention."

Blackman told his original trial he had believed the victim was already dead and he had been taking out his anger on a corpse.

Reducing the conviction earlier this month, the judges said Blackman had suffered from "quite exceptional stressors" which increasingly affected him the longer he was in command.

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