HARRY DUNN'S family has criticised lawyers acting on behalf of the US intelligence officer's wife accused of killing their son after they claimed she had "co-operated fully" with the investigation.

The family has led a high-profile campaign for justice after Anne Sacoolas returned to the US after the car she was driving collided with the 19-year-old's motorbike on August 27.

Sacoolas, 42, and her family had been based at RAF Croughton in Northamptonshire and she sparked public outrage after claiming diplomatic immunity due to her husband's job.

It was only after she left the UK on a military flight directly from the air base that the Foreign Office wrote to the family to say immunity in her case was not valid.

The Crown Prosecution Service announced on Friday that Sacoolas has been charged with causing death by dangerous driving.

Prosecutors have begun the extradition process to bring her back to the UK, a decision the US government labelled "disappointing" and "unhelpful".

But Prime Minister Boris Johnson has said the "law should take its course" and the Government will press the issue with the US "at every level".

A statement from Amy Jeffress, Sacoolas's lawyer, said she had "co-operated fully with the investigation", adding, "Anne will not return voluntarily to the United Kingdom to face a potential jail sentence for what was a terrible but unintentional accident."

Dunn family spokesman Radd Seiger urged Sacoolas to "put that defence forward in court here rather than ventilate it publicly".

The US State Department maintained that Sacoolas had diplomatic immunity at the time of the incident.