A coroner has called for a statutory inquiry into the "flawed" MoD investigation into a Kent soldier's 'friendly fire' death in Afghanistan.

Coroner Roger Hatch has promised to write to the government after Spr Mark Smith was killed by a stray smoke shell on July 26, 2010.

Th Swanley resident, who served with the Maidstone-based 36 Engineer Regiment, was hit by a 105mm shell in the Sangin area of Helmand district.

He was working as part of a team in the army's Counter Improvised Explosive Device (C-IED) Task Force.

But, after a four-day inquest at Gravesend Old Town Hall, the coroner delivered a narrative verdict, saying: "There should now be a statutory inquiry into the failure of the investigation into Sapper Smith's death.

"He died in the course of active service when a smoke shell fell short."

But, he said there had been a "a systematic failure" in the collection of evidence, which left questions unanswered and, potentially, dangers remaining for soldiers who use the ammunition that has not been tested.

He said the MoD had a duty to rectify the failure.

Mr Hatch was speaking after the inquest heard Spr Smith had been deployed in support of the 40 Commando Royal Marines Battle Group on the day of his death.

The team had been targeted with small arms fire, and a smoke screen was requested to allow them to get to a strategic building known as Compound 22.

But after a shell earlier "went rogue" a final shell accidentally hit the compound, where the team now were, and instantly killed Spr Smith.

Sapper Smith's body was repatriated to RAF Lyneham

Giving evidence, Sapper Shaun Dean, said: "There was a big whoosh. It was really quick. It takes longer to say it.

"The next thing I heard was screaming.

"I had been thrown forward and it was really hard to see because of all the dust."

Speaking after the inquest, his family said they believed his death was preventable.

They added: "The evidence shows that a broken weather computer and use of incorrect data from earlier in the day resulted in Mark's death.This is compounded by the fact that the investigation was flawed.

"there has been a systematic failure in the collection of that evidence that leaves questions unanswered and potentially dangers remaining for soldiers who use the ammunition that has not been tested" – coroner roger hatch

"Key evidence has gone missing and has never been returned to the UK. We will probably never know if the ammunition failed on that fateful day.

"We do not blame the soldiers involved in the operation for whom we have the upmost admiration.

"However, we believe the Ministry Of Defence needs to take responsibility for this so as to avoid further deaths.

They said they were extremely grateful to Spr Smith's comrades who had given evidence, and were "immensely proud" of him and the guys with him on the mission.

They added: "We know that the mission they were engaged in in Helmand was an extremely tough one.

"We are aware of the constant threat of enemy fire and IEDs. The stresses involved must be enormous."

At Mark’s old barracks in Maidstone, where the Royal Engineers are based, his friends and comrades have put up a bench.

Inscribed on the bench it says ‘Mark Smudge Smith - Legend’.