The alleged killer of teenage motorcyclist Harry Dunn is “wanted internationally” after an Interpol Red Notice was issued for her arrest, a family spokesperson has said.
The 19-year-old died when his motorbike crashed with a car outside a US military base in Northamptonshire in August last year.
Anne Sacoolas, the alleged driver of the car and the wife of a US intelligence official based at RAF Croughton, claimed diplomatic immunity following the crash and was able to return to her home country, sparking an international controversy.
Sacoolas, 42, was charged with causing death by dangerous driving in December but an extradition request submitted by the Home Office was rejected by US secretary of state Mike Pompeo in January.
His family have fought a hard battle for justice and on Monday welcomed to the news that Sacoolas was now a "fugitive on the run”.
Harry's mother Charlotte Charles said: "It’s been a terrible time for us. We are utterly bereft and heartbroken and miss our Harry every minute of every single day.
"This is important news that Radd has just passed on to us and we are in pieces. I just want to urge Mrs Sacoolas to come back to the UK and do the right thing. Face justice and maybe then our two families can come together after the tragedy and build a bridge."
The family's spokesperson, Radd Seiger said in a statement: "Northants Police have confirmed to me that an Interpol red notice has now been circulated worldwide in respect of Anne Sacoolas.
"It renders her a fugitive on the run and it means that she would be arrested and returned to the UK the minute she attempts to set foot out of the USA.
"More importantly, it means that the British authorities have concluded that she did not have diplomatic immunity at the time of Harry’s death," he said.
He added: "I am sure that both families have suffered for far too long and it is time for her to do the right thing and come back."
In an email to Mr Dunn's parents from Northamptonshire Police, the force said “the wanted circulations should be enacted” should Sacoolas leave the US.
On April 30, a spokesperson for the US State Department reiterated its position that at the time of the accident, and for the duration of her time in the UK, the driver had immunity from criminal jurisdiction.
Last month, ITV News learned the Foreign Office Dominic Raab had failed to tell police Ms Sacoolas was leaving UK.
A Foreign Office official said there was "not much mileage" in keeping Harry's alleged killer and her family in the UK just three weeks after his death
According to the Interpol website, a Red Notice is a request for "law enforcement worldwide to locate and provisionally arrest a person pending extradition, surrender, or similar legal action."
It is not an international arrest warrant and usually applies to the country where the crime was committed rather than the home country of the individual.