Police investigating the death of Harry Dunn have told the teenager’s parents that an email saying their son’s alleged killer is “wanted internationally” may have been a reference to a European Arrest Warrant.

In response to a complaint lodged by the family’s spokesman on Wednesday, the teenager’s parents were also informed the email from Northamptonshire Police sent to them earlier this week “appeared” to reference the warrant and “the circulation of Anne Sacoolas on the police national computer and nothing more”.

The PA news agency understands authorities have still not categorically denied to the parents the existence of an Interpol Red Notice in respect of Sacoolas.

Family spokesman Radd Seiger said the wording of the original police email made it “crystal clear” to lawyers acting on behalf of the parents that a Red Notice had been issued for the suspect.

Mr Dunn was killed when his motorbike crashed into a car outside a US military base in Northamptonshire on August 27 last year.

Sacoolas, 42, the wife of a US intelligence official based at RAF Croughton, claimed diplomatic immunity after the crash and was able to return to her home country.

She 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, a decision the State Department has since described as “final”.

Mr Seiger said he believed police were “forced” to issue a statement on Wednesday, which said: “We wish to make it absolutely clear that, at no point, has Northamptonshire Police informed the family spokesperson for the Dunns, Radd Seiger, that an Interpol Red Notice has been issued in respect of Mrs Anne Sacoolas.”

The family’s spokesman said the lack of clarity in the statement and the suggestion Mr Seiger had “made the whole thing up” had caused “enormous distress” to Mr Dunn’s parents, Charlotte Charles and Tim Dunn.

A response sent to the family spokesman from the office of the Northamptonshire Police and Crime Commissioner said: “It appears that the reference in this email to ‘wanted internationally’ was a reference to (a police officer’s) knowledge of the existence of a European Arrest Warrant and the circulation of Mrs Sacoolas on the police national computer and nothing more.”

Mrs Charles told PA: “It has been a rollercoaster of a week.

“We had the good news about the Red Notice on Monday, but were then kicked in the stomach on Wednesday by the police’s statement.

“It is an absolute disgrace the way we are being treated. Inhumane and cruel doesn’t come close and we are all beside ourselves with stress, worry and anxiety.

“That doesn’t appear to be a concern to those in authority.

“We get all our love and support from Radd, our friends and family, the media and our supporters across the nation and around the world.

It is an absolute disgrace the way we are being treated

“It is they who are keeping us going.

“As for those in authority, they need to have a good long look at themselves. It is as if the victims’ code and our rights don’t exist.”

Mr Seiger, who practised law for 27 years, told PA: “It was Northamptonshire Police’s officer who wrote to the parents on Monday using words which to any trained eye like mine, and the parents’ leading solicitor and QC, make it crystal clear that a Red Notice has been circulated in respect of Anne Sacoolas.

“There is no doubt about that whatsoever.

“She is now a fugitive who is to be located and provisionally arrested and returned to the UK to face her charge of causing Harry’s death by dangerous driving.

“She is being harboured in the USA by President Trump and Secretary Pompeo.”

He continued: “The shame of all this is that the CPS, the police and Harry’s family clearly all want the same thing, which is what all right-minded and reasonable people on both sides of the Atlantic want, which is simply for Anne Sacoolas to do what any of us would have to do, to answer the charge laid against her. No more, no less.

“Regrettably, we cannot include Boris Johnson’s government in that group, given that they unlawfully allowed her to leave and then have been in a desperate battle to keep their breach of legal protocol covered up.

“The parents hate what happened to their son. They do not hate Mrs Sacoolas.

“They are highly confident that she will get a fair trial when she is back. That is the sort of country and people that we are.”