The family of Harry Dunn have accused a police chief of attacking them by “calling out” their spokesman in a press conference.
Northamptonshire Police Chief Constable Nick Adderley urged Radd Seiger to “exercise constraint” after the spokesman publicly criticised the work of the force and the Foreign and Commonwealth Office (FCO).
But the teenager’s parents said Mr Adderley may “live to regret” the comments he made on Tuesday about Mr Seiger, adding that their approach has been “essential” in searching for justice for their son.
US suspect Anne Sacoolas was allegedly driving on the wrong side of the road when she hit the 19-year-old’s motorbike outside RAF Croughton in Northamptonshire on August 27.
After being told she had diplomatic immunity from prosecution, Mrs Sacoolas left the UK on a US Air Force plane on September 15 without giving an account to police.
Responding to Mr Adderley’s comments, a statement from Mr Dunn’s family given to the PA news agency read: “Firstly, we wish to make it clear that Nick Adderley has our full respect as one of the country’s leading and most progressive heads of police.
“That said, we wonder whether he will live to regret making some of the comments he made yesterday, particularly in calling out Radd Seiger and our public campaign for justice.
“He said it wasn’t helpful. We understand why the authorities may feel that the approach we have taken is unhelpful, but we feel it has been dignified and respectful at all times, and has not only been helpful to our cause of searching for justice for Harry, but frankly essential.
“By calling out our spokesman, he is effectively attacking us and our approach. We have also fact-checked the timeline he presented and it unfortunately contains several inaccuracies.”
Mr Adderley told the press conference that the investigation into the death of Mr Dunn was “amongst the best I have ever seen”.
But the family maintain they would be no further along in their search for justice had they not made their many public appearances.
The statement continued: “Were it not for Radd Seiger, the help of the media in giving a platform for us to speak from, and the overwhelming support of the public – not only here in the UK, the USA but right around the world – we would have been no further on in our search.
“It can be no coincidence that, in the last two weeks, following our intensive efforts, the issue of Mrs Sacoolas’s indemnity has fallen by the wayside.
“We have held high-profile meetings with the most senior of politicians in London and Washington, including an extremely helpful meeting yesterday with Emily Thornberry, shadow foreign secretary, and Shami Chakrabarti, shadow attorney general, and the police are now to interview Mrs Sacoolas under caution.
“None of that would have happened were it not for the campaign, we feel.
“Firstly, Mrs Sacoolas must return to the UK to face the music. That is non-negotiable.
“Secondly, it appears to us that at the very least the FCO and Northants Police have not put their best foot forward. We are entitled, like any other victim of crime, to be supported by the authorities and to be kept updated on the progress of the case.
“As is clear to the thousands and thousands of people who have sent us supportive messages, that sadly for us has just not been the case.
“We note Nick Adderley defended his team’s actions robustly. That is all well and good. So has the Foreign Secretary. But they are both overlooking the fact that we do not feel supported and plainly have not been kept updated.
“Everything that has happened on their part follows on immediately from one of our many public appearances and that is just not good enough.”
The family added that if the police feel they cannot give answers to the questions they have been asked about the investigation, the matter will be left in the hands of lawyers.