Harry Dunn, 19, was riding his motorbike on August 27 when he was struck by Anne Sacoolas, who was driving on the wrong side of the road near the RAF Croughton air force base in Northamptonshire, which is used by the US military. Foreign Minister Dominic Raab said on Monday that the rules which allowed Sacoolas to leave the country were being looked at.

“I have already commissioned a review of the immunity arrangements for US personnel and their families at Croughton,” Raab told the House of Commons, adding that he does not believe that the current rules are “right” and that the review process will look at how to avoid having them be used in such a way again.

US officials actually warned their British counterparts that Sacoolas would leave the UK following the fatal incident, but the British were legally unable to prevent her departure, Raab said.

Dunn’s family have since pressured police and the courts to continue their investigation, and possibly extradite Sacoolas to face charges. Though Sacoolas claimed immunity due to her husband’s position at RAF Croughton, he has since left the base, and the Crown Prosecution Office stated that Sacoolas’ immunity from prosecution no longer applies.

Family lawyer Raad Seiger urged the CPS to make a quick decision on filling an extradition request with US authorities.

“That would be one giant step towards achieving closure,” he said on Saturday. “It's not a game – this family are grieving.”

Prime Minister Boris Johnson has raised the question of sending Sacoolas back to the UK with the White House.