The Navy is not planning to publish the findings of an internal inquiry into the killing of an Afghan fighter by a Royal Marine, according to reports.
Sergeant Alexander Blackman quoted Shakespeare as he shot his victim in the chest at close range with a 9mm pistol after the Afghan had been seriously injured in an attack by an Apache helicopter.
He is serving an eight-year jail sentence after being convicted by a court martial of murder over the killing, which happened in Helmand province in 2011 while he was serving with Plymouth-based 42 Commando.
The Daily Mail reported Vice Admiral Sir Philip Jones, fleet commander of the Royal Navy, sent an email to other military chiefs in July to say the inquiry report will remain a "controlled document", adding the findings "may make uncomfortable reading for some".
Author Frederick Forsyth, who is behind a campaign to launch a legal review of Blackman's conviction, said the decision not to publish is "disgraceful".
According to the Mail, Sir Philip's email said: "The full review will remain a controlled document. Unsurprisingly, however, knowledge of the review is in the public domain and there have been requests under the Freedom of Information Act for it to be published.
"That is not the intention but we will be releasing a redacted version of the executive summary by the end of September."
The paper printed part of the executive summary, which concluded Blackman "allowed professional standards to slip to an unacceptably low level".
Forsyth said: "It is disgraceful that Navy top brass plan to sweep under the carpet evidence which could help Sgt Blackman."
Speaking from jail, Blackman said the killing was a "split-second mistake".
At the time of shooting, Blackman told the Afghan fighter: "There you are. Shuffle off this mortal coil, you c***. It's nothing you wouldn't do to us."
He then turned to comrades and said: "Obviously this doesn't go anywhere, fellas. I just broke the Geneva Convention."
During the trial Blackman was known as Marine A.
He denied murder, saying he believed the victim was already dead and he was taking out his anger on a corpse.
On top of his sentence, he was also "dismissed with disgrace" from the Royal Marines after serving with distinction for 15 years, including tours of Iraq, Afghanistan and Northern Ireland.
Blackman's conviction challenge was rejected by the Court Martial Appeal Court, although his minimum term was cut to eight years because of the combat stress disorder he was suffering at the time of the incident.
An online petition calling for his conviction to be quashed gained more than 100,000 signatures late last year.