The inquiry is looking at alleged unlawful killings by British troops in Afghanistan
The inquiry is looking at alleged unlawful killings by British troops in Afghanistan AFP

UK special forces allegedly had a policy of executing "fighting age" males in Afghanistan even if they posed no threat, an independent inquiry probing claims of unlawful killings was told on Monday.

The inquiry, which opened in March but has now started substantive hearings at London's Royal Courts of Justice, is investigating accusations about the special forces' conduct in Afghanistan between 2010 and 2013.

It is examining so-called deliberate detention operations during that period and how allegations of unlawful killings were investigated by Britain's military police, in particular whether there were any cover-ups.

The independent inquiry follows legal challenges by the families of some of the dozens of people allegedly murdered by UK special forces during night raids.

It is set to hear submissions on behalf of the families of 33 people, including eight children, who were allegedly killed.

Detailing some of the cases being reviewed, lawyer to the inquiry Oliver Glasgow revealed a British soldier was said to have subsequently admitted "there was a policy in special forces to kill fighting age males".

Glasgow noted the claim had been discovered in a "restricted security" dossier recovered years later that detailed a conversation with the soldier.

The lawyer added there were also accusations that Afghan partner units "refused to serve with UK special forces due to their behaviour".

"Let there be no misunderstanding for those who have something to hide," Glasgow said in his opening submission.

"The inquiry will use all its powers to make sure that if there is credible information of wrongdoing ... no matter how senior their position, they are referred to the relevant authorities."

Two military police probes -- codenamed Operation Northmoor and Operation Cestro -- are set to be scrutinised.

Families who allege unlawful killings by Britain's special forces urged the inquiry to "provide us with the truth" before Monday's hearings.

The inquiry is being led by senior judge Charles Haddon-Cave.

He has previously said it is important wrongdoing be "referred to the relevant authorities for investigation" while "those who have done nothing wrong should rightly have the cloud of suspicion lifted from them".

Other countries' special forces have also faced allegations of unlawful killings in Afghanistan.

In Australia, a 2020 military investigation found special forces personnel "unlawfully killed" 39 Afghan civilians and prisoners, revealing allegations of summary executions, body count competitions and torture by Australian forces.