SAS soldiers in Afghanistan killed dozens of detainees and unarmed men in suspicious circumstances, according to a BBC investigation.
The broadcaster reports that military files suggest one unit may have unlawfully killed 54 people.
And the BBC found evidence suggesting the former head of special forces failed to pass on evidence to a murder inquiry. It says that General Sir Mark Carleton-Smith was briefed about the alleged unlawful killings but did not pass on the evidence to the Royal Military Police.
BBC Panorama analysed hundreds of pages of SAS operational accounts, including reports covering more than a dozen “kill or capture” raids carried out by one SAS squadron in Helmand in 2010/11.
Individuals who served with the SAS squadron on that deployment told the BBC they witnessed the SAS operatives kill unarmed people during night raids.
They also said they saw the operatives using so-called “drop weapons” – AK-47s planted at a scene to justify the killing of an unarmed person.
Several people who served with special forces said that SAS squadrons were competing with each other to get the most kills.
The Ministry of Defence said it could not comment on specific allegations, but that declining to comment should not be taken as acceptance of the allegations’ factual accuracy.
An MOD spokesperson said that British forces “served with courage and professionalism” in Afghanistan and were held to the “highest standards.”
Reacting to the BBC investigation, the Stop the War Coalition said the evidence brought to light is further damning proof that the military occupation of Afghanistan was an utter failure.
It said: “The primary victims of that failure were the people of Afghanistan who have suffered immeasurably from these war crimes. The reports detail over one-hundred murders including night raids on unarmed victims, the killing of detainees and the ensuing cover-up. Stop the War demands that those responsible for these crimes and the whitewash that followed are brought to justice for their actions.
“The fact that General Sir Mark Carleton-Smith, the former head of UK Special Forces, who is accused of leading the cover-up was promoted to Chief of the General Staff is yet another disturbing indictment of the British Army. The ‘reward for failure’ culture in that institution seemingly knows no bounds.”
Stop the War Convenor, Lindsey German, added: “These revelations are horrific and were obviously well known at the highest levels of the British Army. We have had 20 years of lies about Afghanistan, not least that it was a humanitarian intervention.
“These killings were war crimes and were covered up. There should be trials of those responsible including those in government and military who knew about this. But I won’t be holding my breath given the impunity over Blair and Iraq.”
Watch Panorama: SAS Death Squads Exposed: A British War Crime?