The conviction of a Royal Marine found guilty of murdering an injured Taliban fighter could be quashed as the judge mishandled his trial, it is reported.
Judge Advocate General Jeff Blackett, the country's most senior military judge, has been criticised by the Criminal Cases Review Commission (CCRC) for not offering a military jury the chance to convict Sergeant Alexander Blackman of manslaughter, the Daily Telegraph said.
Blackman, 42, previously known as Marine A, is serving a life sentence for murdering a wounded Afghan captive in 2011 in Afghanistan's Helmand province while serving with Plymouth-based 42 Commando.
But a review concluded he faces the "real possibility" of having his conviction quashed following the presentation of new evidence.
His case has been referred to the Courts Martial Appeal Court.
According to the leaked report, the CCRC, which investigates possible miscarriages of justice, said Judge Blackett was guilty of a "material irregularity" in the original trial, due to an "apparent failure to recognise the position regarding manslaughter during the trial and to direct the board appropriately", the Telegraph said.
It reportedly adds: "Due to the failure to leave to the board the option of returning a verdict of guilty to unlawful act manslaughter, if the board was satisfied that, factually, Mr Blackman's shot had hastened the death of the victim, the CCRC considers that there is a real possibility that the Court of Appeal would find Mr Blackman's conviction to be unsafe."
The Telegraph said the CCRC also criticises Blackman's original legal team for "deficiencies in the standard of defence" during his 2013 court martial and that it failed to ask the judge to give the jury the option of convicting him of manslaughter.
But the review body also said legal precedents suggested it was the "ultimate responsibility of the trial judge" to be aware of the possibility.
Blackman, from Taunton, Somerset, was found guilty of murder at a court martial in Bulford, Wiltshire, in 2013 and sentenced to life with a minimum term of 10 years.
But he won the right to appeal last month following the presentation of new evidence relating to his mental health at the time of the killing - and the fact that an alternative verdict of unlawful act manslaughter was not available during the trial.
He was later denied bail ahead of the challenge to the conviction.