A Territorial Army soldier who claimed he stole a rifle and ammunition after suffering war-zone trauma in Afghanistan has been jailed for five years after a judge ruled he lied about his experiences at war.

Corporal Harry Killick, 37, pleaded guilty to possessing a prohibited weapon and stealing a firearm and ammunition from a TA barracks in Brighton in January.

He claimed he was suffering from post-traumatic stress disorder (PTSD) after witnessing people killed and injured during a tour of duty lasting just under six months.

Killick faced a mandatory jail term of at least five years but his lawyer suggested he be handed a more lenient two-year suspended jail sentence with a requirement he undergo therapeutic treatment.

Judge Anthony Scott-Gall was asked to apply "exceptional" circumstances to Killick who had told police, the probation service and psychiatrists about horrors he had seen in Afghanistan.

Following his pleas of guilty and after mitigation was made on his behalf in court, sentencing was adjourned earlier this year to establish appropriate possible treatments for Killick.

Today Judge Scott-Gall, sitting at Lewes Crown Court at the end of a Newton hearing after Killick's version of events was called into question, concluded that he had lied about his time in Afghanistan.

The judge said: "Why would Harry Killick, a top-rate soldier, lie and exaggerate about events?

"Certainly not to get himself out of a prison sentence, it's submitted, and certainly not to reduce a sentence of five years.

"In many areas which have been covered, the defendant has been accurate and truthful, but in my judgment, in the critical areas, he has not.

"I'm quite satisfied that this defendant began this process by telling lies and he was hoisted to some extent ... and has sought to continue these lies because he had no other alternative.

"I hope I'm not being unfair to members of his family who no doubt support him to the hilt, hence the Help Harry campaign."

Killick's lies included that he had witnessed comrades from the Princess of Wales' Royal Regiment (PWRR) killed and injured.

He also insisted he had to take part in the grisly task of retrieving DNA from the body parts of an insurgent killed in a battle.

Following the Newton hearing which heard evidence from Killick's military colleagues, Judge Scott-Gall found a number of lies and exaggeration in his accounts.

The judge said there was only one fatality during the tour and that was of a soldier unconnected to Killick's platoon, 5 Platoon of the PWRR.

Judge Scott-Gall said: "That single incident happened out of sight of the defendant. He was nowhere near it and had no responsibility to what happened to (the dead soldier)."

There was also "no basis in fact" as to why Killick should assume any guilt for the fatality, as he had claimed, the judge added.

The judge also found no evidence to support Killick's claim that he had been asked to retrieve DNA from a dead insurgent.

"Harry Killick would have seen the deceased insurgent but he himself wasn't instructed in any way to handle any part of the deceased insurgent to bring back identifying material," he said.

The judge also said there was "cogent evidence" that no indifference was shown by an Army superior towards him. Instead, there had been "genuine help, genuine support" for Killick, the judge said.

The court heard that the trigger for the theft from the barracks came on October 19 2012 after Killick was told he would not be joining a shooting practice weekend.

On the day of the thefts, Killick's estranged wife, Nicola, reported her concerns to his superiors about his mental state since returning from action.

Killick had signed his car over to her, cancelled his bank cards and there were concerns that he had cut ties with his father and friends. He also told his children he would not be seeing them.

The court was told that Killick had "social needs" following the breakdown of his marriage and had racked up around GBP20,000 in debts.

His relationship with his girlfriend had also broken down, and he was coming to terms with having nowhere to live on demobilisation while suffering adjustment problems on "civvy street".

Killick's forced withdrawal from the shooting practice weekend would have come as a blow as he needed to attend to gain clearance. He also had to abandon plans to work at the Olympics.

Judge Scott-Gall said: "There is clear evidence as to why the defendant took the course that he took, having suffered mounting disappointment in the only life he had known i.e. the life of the TA where he was considered a valued member of the team, value which seemed to be evaporating."