High Court judges have been urged to watch a video showing multiple beheadings "carried out by the Taliban".
The request has come from Mohammed Rafi Hottak, who says his own life remains in danger after recruiting hundreds of interpreters for the British military in Afghanistan.
Mr Hottak describes in a statement to the court how the video "broke my heart".
He says two of the six young men seen having their heads sawn off with a handheld knife were friends and old room-mates specially targeted after they chose to work as interpreters with US forces.
Mr Hottak and another ex-interpreter, referred to as AL, are accusing the UK Government of unlawfully failing to offer adequate assistance to former Afghan interpreters who worked for them.
Lord Justice Burnett and Mr Justice Irwin, sitting in London, were told by their barrister Ben Jaffey that each had given "loyal, important and dangerous service" for the UK armed forces.
As a result both they and their families had suffered serious injuries in Taliban attacks.
But they and other interpreters like them were being discriminated against and given less favourable treatment and assistance than Iraqi interpreters whose lives became endangered working for the British in the Iraq war.
The Foreign and Commonwealth Office (FCO) and Ministry of Defence are fighting the claim.
They say it is "misconceived" and that schemes have been put in place appropriate to "the circumstances in Afghanistan".
Mr Hottak wants the judges to view the video as evidence of the threat still facing former "locally engaged staff" employed by the British and other members of the International Security Assistance Force (Isaf), the Nato-led security mission in Afghanistan.
He was seriously injured when the vehicle he was in was blown up by a roadside bomb while he was on patrol with British forces in Helmand in 2007.
Between February 2008 and October 2009 he was based in Kabul to recruit other military interpreters.
Mr Hottak said in his statement his job was to determine whether applicants had good enough English and Pashto - the language spoken in the south of the country, including Helmand province - for the role.
Twice he was attacked and received death threats from the Taliban. He fled to the UK and was granted refugee status in 2013.
AL remains in Afghanistan in hiding.
Mr Hottak stated: "I was extremely high profile and well known, as a result of my work interviewing large numbers of candidates.
"I do not doubt that some of the people I interviewed were sympathetic with the Taliban, and would have been reporting back on what they had seen and heard when interviewed."
One interpreter, Mumtaz Khan, was kidnapped by the Taliban and tortured and shown pictures of AL and Mr Hottak and told: "This is who we really want". Mr Khan was later granted refugee status in Canada.
In August 2009, Mr Hottak's commanding officer wrote a letter recording the loss of four interpreters who died while deployed over a six-month period, said Mr Hottak.
"I resigned because of the death threats I was facing from the Taliban as a direct result of working in a high profile position for Her Majesty's Government based in a major military camp."
Referring to the video of the Taliban executions, Mr Hottak said a slogan in Pashto flashed across the screen meaning: "The Consequences for the Spies".
He stated: "I recognised two of my friends amongst the men who were beheaded.
"They were my room-mates for four months when I was working for British Forces as part of Isaf in Kunar Province, Afghanistan.
"I cannot describe how I felt when I watched this video for the first time, even though some time has passed since my friends were killed, it broke my heart.
"I could not sleep properly and had awful nightmares. I fear for my life here in the UK and I feel terrified for my family back in Afghanistan.
"This video shows the extreme violence and brutality which interpreters face because of their work for foreign forces."
Mr Hottak said while he was working in Kabul in 2007 the UK forces received the body of a dead interpreter.
"Luckily he had not been beheaded. He had just been shot sixty times and whipped with a chain."