The wife of a US diplomat has left the UK after becoming a suspect in a fatal hit-and-run crash which killed a teenager.

Harry Dunn, 19, was riding a motorbike when he collided with a car driven close to RAF Croughton in Northamptonshire on August 27. He suffered multiple injuries and died in hospital.

A 42-year-old woman was being investigated for causing death by careless driving . Police believe she pulled out of the airbase onto the wrong side of the road before colliding with Mr Dunn, according to the Times.

The woman has now been flown home as she is considered by the US to have diplomatic immunity.

Dominic Raab, the foreign secretary, has called the US ambassador in London to "express his disappointment".

Police said the suspect previously confirmed "that she had no plans to leave the country in the near future" and that the force was working "through diplomatic channels" to ensure the case continues.

Speaking to Sky News, Mr Dunn's mother Charlotte Charles called for justice.

She said: "Everyone loved him, we're utterly broken inside and out, everything hurts day and night, it's an effort to do anything, I ache from it, every limb, every internal organ hurts."

She added: "We don't know how we can start to grieve for him.

""We have nothing. No justice. We have nothing to put our minds at rest that she's even remorseful."

In its own statement provided to Sky News, the US Embassy in London offered its "deepest sympathies" to Mr Dunn's family following the accident "involving a vehicle driven by the spouse of a US diplomat assigned to the United Kingdom".

It added: "Embassy officials are in close contact with the appropriate British officials on this matter.

"Due to security and privacy considerations, we cannot confirm the identity of the individuals involved, but we can confirm the family has left the UK."

Mr Raab added: "I wish to offer my condolences to the family affected by this tragic incident.

"I have called the US Ambassador to express the UK's disappointment with their decision, and to urge the embassy to re-consider it."

Superintendent Sarah Johnson from Northamptonshire Police said: "Northamptonshire Police followed all of its usual procedures following the incident, including liaising closely with the suspect, who engaged fully with us at the time and had previously confirmed to us that she had no plans to leave the country in the near future.

"Due process was also followed in seeking the necessary documentation to allow for the arrest and formal interview of the suspect, and the force is now exploring all opportunities through diplomatic channels to ensure that the investigation continues to progress.

"We are also working closely with the Foreign & Commonwealth Office in an effort to come to a resolution regarding this matter.

"Harry Dunn's family deserve justice and in order to achieve this, a full and thorough investigation, with the assistance of all parties involved, needs to take place.

"Northamptonshire Police is committed to ensuring justice for Harry and specially trained officers continue to support the Dunn family in their loss, including keeping them fully informed of all developments in the investigation."