The shocking allegations emerged in Operation Northmoor, a classified multimillion pound probe run by the Royal Military Police.
Senior defence sources have said that evidence gathered on the elite Who Dares Wins regiment’s alleged war crimes are “credible”, according to the Sunday Times.
A source close to Operation Northmoor, which is being run from a secure bunker at RAF St Mawgan near Newquay, Cornwall, said there was strong evidence unarmed Afghan civilians were murdered rather than captured during night raids on their homes.
In one allegation dating back six years, which is now being investigated, SAS commandos are accused of handcuffing and hooding some of the victims before later shooting them dead.
After the alleged murders, SAS mission reports are said to have been altered to make it look as if its Afghan Special Forces partners, rather than British soldiers, carried out the shootings.
That meant the killings were not investigated at the time.
But drone and other footage obtained by investigators, nicknamed “kill TV”, is said to show British troops opening fire on unarmed people.
An examination of bullets found in the victims’ bodies showed they were a type used by the SAS.
There were also claims SAS troopers planted Russian Makarov pistols on victims’ bodies and then took photos of the corpses to suggest the British Special Forces had killed armed Taliban insurgents in self defence.
Jeremy Corbyn branded the allegations “extremely serious” and called for them to be “fully investigated”.
The Labour leader added: “Our Armed Forces have a reputation for decency and bravery.
“If we do not act on such shocking allegations we risk undermining that reputation, our security at home and the safety of those serving in the armed forces abroad.
“Our values and respect for the rule of law require full accountability.
“We owe it to our Armed Forces and the victims and their families to ensure that a thorough investigation takes place.
“There can be no question of a cover up. The Government must now establish an independent inquiry into what has taken place.”
A MoD spokesman said: “The Royal Military Police has found no evidence of criminal behaviour by the Armed Forces in Afghanistan.
They have discontinued over 90% of the 675 allegations made and less than 10 investigations remain.
“Our military served with great courage and professionalism and we proudly hold them to the highest standards. Where allegations are raised it is right they are investigated.”
Operation Northmoor was set up in 2014 and involves more than 100 Royal Military Police officers.
It has since been investigating dozens of alleged unlawful killings by SAS forces between 2010 and 2013.
Detectives had been looking into 52 alleged killings, but are now examining just one incident which involved four family members being shot dead during a night raid in Helmand province in 2011.
Written by: Mirror