The mother of a British officer killed by the Taliban in Afghanistan has said that she wants the world to see the video showing the moments leading up to her son's death.

Lieutenant Mark Evison, 26, died in May 2009 as he led his platoon from 1st Battalion Welsh Guards out on a patrol to secure compounds and "dominate" the Haji Alem area of Nad-e-Ali district, Helmand Province, Afghanistan.

But Lt Evison was shot by a Taliban sniper as he broke cover to try and get a radio signal.

Only surgery could have stopped him from bleeding to death in the field. One of the medical reports quoted in the inquest said: "Only a vascular surgical clamp across the damaged artery could stop the bleeding."

Lt Evison's mother Margaret said: "Even if they said 'well we don't know' or it was human error, I would be very forgiving if it was human error. But if it was that there weren't enough helicopters and a soldier was left bleeding to death 20 kilometres from a hospital in Afghanistan, then I think it needed looking at."

In a statement the Ministry of Defence said: "Our sympathies remain with Mrs Evison following the death of her son, Lt Mark Evison. The independent coroner concluded that the time taken for a medical helicopter to arrive did not contribute to Lt Evison's death as his injuries were, sadly, unsurvivable."