British police officers are due to travel to the US to interview the suspect in a crash which killed teenager Harry Dunn.
The 19-year-old motorcyclist died after his bike crashed into a car driven by Anne Sacoolas outside RAF Croughton in Northamptonshire in August.
Sacoolas – the wife of a US diplomat – travelled back to America following the crash, claiming diplomatic immunity.
Radd Seiger – a spokesman for Dunn’s family – said the news that Northamptonshire Police was sending detectives to the US was “further compounding the family’s misery”.
“Yesterday the family were told the police had passed their file to the CPS (Crown Prosecution Service) yet tonight were informed that the police were travelling to the USA to interview Mrs Sacoolas,” he wrote on Twitter.
“Those two statements appear to be contradictory on the face of it, further compounding the family’s misery.”
It comes the day after foreign secretary Dominic Raab revealed that the US had warned the UK that 42-year-old Sacoolas would leave the country after the crash.
However, objections from the Foreign Office were disregarded, he told the House of Commons on Monday.
Raab said he had commissioned a review into immunity arrangements for US personnel and their families at the RAF Croughton annex in light of the case.
There are “no barriers to justice being done” for Harry, he added.
Meanwhile, Raab told MPs that the government believes diplomatic immunity “clearly ended” for Sacoolas when she left the country for America.
Dunn’s parents – Charlotte Charles and Tim Dunn – travelled to the US last week in an attempt to put pressure on authorities to return Sacoolas to the UK.