A special deal is in place between the UK and the US which gives diplomats and their families based at RAF Croughton diplomatic immunity, Sky News understands.
Usually, diplomatic immunity only covers those diplomats and their dependants based in London.
However, Sky News has been told there has been a special arrangement in place as early as 1994 between the UK and US for this particular base in Northamptonshire.
The revelation comes after 19 – year-old Harry Dunn was killed in a head on collision with a woman who had just driven out of the American spy base.
Police believe she was on the wrong side of the road during the incident on 27 August.
Government ministers have called for the American woman to return to the UK to answer questions after she claimed diplomatic immunity and left the country.
Harry’s father, Tim Dunn, told Sky News: “It’s appalling, you can’t have this precedence where you can have this immunity.
“It’s basically saying you can do what you like and you’ll be okay – it’s wrong. That can’t be right.”
Harry’s mum, Charlotte Charles, called it ” inhumane. “
Police told Sky News their initial findings showed that Harry was riding his motorbike on the correct side of the road, but that a woman, who pulled out of the base onto the wrong side of the carriageway, hit him head-on .
On Friday, Sky News first revealed that the suspect is the wife of a US diplomat – dependants of diplomats can also be covered by immunity.
Harry’s family have launched a crowdfunding campaign to fight for justice, with one woman alone already pledging £ 5, 000.
Business Secretary Andrea Leadsom, who is the family’s local MP in South Northamptonshire, has made an appeal for the woman to offer “closure” to Harry’s family.
She told Sky News: “I met with Harry’s family on Friday and they’re totally devastated.
“It’s just the most appalling tragedy and my heart goes out to them. Anybody who met them would realize this is just heartbreaking.
” Obviously I’m going to do everything I can to make sure they get justice for Harry.
“But, at the same time, I would appeal over the head of the Foreign Office to the woman; it was an accident from all accounts – obviously I wasn’t there and it needs a police investigation – but surely she must see that this family needs closure.
“So I would urge for anybody who’s involved to come forward and to make themselves available so this family can get closure. It’s just terrible. “
The US embassy has confirmed to Sky News that the woman has left the UK.
It is understood that someone on the American side told the family to go back to the US.
A spokesperson said: “This kind of case receives intense attention at senior levels and every case is considered carefully given the global impact such decisions carry.”
Ms Leadsom’s fellow cabinet minister, Robert Jenrick – the housing, communities and local government secretary – also urged the woman to “answer the questions she needs to”.
He revealed Foreign Secretary Dominic Raab had spoken to the US ambassador to the UK and “made clear our disappointment that the woman involved in this incident has left the UK using diplomatic immunity”.
“The family involved have our absolute assurance that we’re going to do everything we can to resolve this, “Mr Jenrick told Sky News’ Sophy Ridge On Sunday show.
” We want the police to be able to continue their inquiries and for whatever actions they deem fit to be able to take place and for justice to be done. “
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He added: “This is a very serious situation. heart goes out to this family, who now want answers and want justice.
“What I can say is the local MP, who is Andrea Leadsom – the business secretary – has met the family.
“The foreign secretary has offered to meet the family and will do so shortly.
” And he couldn’t have been clearer when he spoke to the American ambassador that we are very disappointed by the way events have turned out and we want to see the US change their minds and this lady come back to the UK t o answer the questions that she needs to. “
Sky News has tried to contact the woman but she has not responded.
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