The family of Harry Dunn have accused the Foreign Office (FCO) of being “engaged in a cover-up” over the teenage motorcyclist’s death.

The FCO has said it has “no plans” to launch a public inquiry despite reports that his alleged killer had worked as a spy for the CIA.

The FCO responded to questions from the 19-year-old’s family on Wednesday – saying the case had been handled “properly and lawfully throughout”.

Mr Dunn’s parents, Charlotte Charles and Tim Dunn, along with family spokesman Radd Seiger, said they now “believe the FCO were complicit” in Anne Sacoolas’s departure from the UK.

The family had demanded answers from Foreign Secretary Dominic Raab as to whether he was notified of Mrs Sacoolas’s history with the CIA and if she was still serving at the time of Mr Dunn’s death.

At Prime Minister’s Questions (PMQs) on Wednesday, Prime Minister Boris Johnson said the Government has been “tirelessly” seeking the extradition of the suspect from the US after he was asked if she was being “shielded from justice because she’s a former CIA officer”.

Mr Seiger had called for a public inquiry into “who knew what and when in government” and into the “deplorable” way the family had been treated.

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

Mrs Sacoolas, 42, the wife of a US intelligence official based at RAF Croughton, was granted diplomatic immunity following the crash and was able to return to her home country, sparking an international controversy.

She was charged with causing Mr Dunn’s death by dangerous driving in December, but US Secretary of State Mike Pompeo rejected an extradition request for her last month.

In PMQs on Wednesday, Labour leader Jeremy Corbyn said: “While the Government was fighting to deport people who legally came to this country as children, the Foreign Secretary refused to tell the family of Harry Dunn the reason why the US is blocking the extradition of a woman who is alleged to have killed him.

“I now ask the Prime Minister straight this question: is Anne Sacoolas being shielded from justice because she’s a former CIA officer?”

Mr Johnson said Mr Raab and himself, plus others in government, have “tirelessly” sought the extradition of Mrs Sacoolas, adding: “We will continue to do so.”

Mr Corbyn said it was widely reported that Mrs Sacoolas “is in fact a CIA operative”, adding: “Now we know the Foreign Secretary misled the Dunn family, who are being denied justice by the US government, will the Prime Minister commit to his removal from office tomorrow in his reshuffle?”

Mr Johnson replied: “The Foreign Office has been told Anne Sacoolas was notified to the UK Government as a spouse with no official role.

“We will continue without fear or favour to seek justice for Harry Dunn and his family and continue to seek the extradition of Anne Sacoolas from the United States.”

In a letter responding to the family’s request for answers, the Foreign Office said: “I understand you have also called for a full public inquiry.

“We are doing everything we can to support Harry’s family and help them get justice and are confident that the case has been handled properly and lawfully throughout.

“We do not plan to hold an inquiry.”

Harry Dunn death
The family of Harry Dunn (left to right) mother Charlotte Charles, stepfather Bruce Charles, family spokesman Radd Seiger, father Tim Dunn and stepmother Tracey Dunn (David Mirzoeff/PA)

Mrs Charles, speaking on behalf of the family, said she believed Mr Raab was not being honest with them.

She said: “We are just struggling to understand what is going on and why the FCO are treating us so badly.

“We should be on the same page as them, fighting the US administration. We are going through an absolutely terrible time nearly six months after Harry’s death as we try to get back on our feet.

“Some of us are trying to get back to work but we are not coping with that and every day is a painful struggle.

“We thought we had bridged the gap with the Government. But they have not been honest us.

“We have been open and honest with them. They are not being that with us.”

A spokesman for the Foreign Office said: “Anne Sacoolas was notified to the UK Government as a spouse with no official role.

“We recognise the grief caused by this tragic accident and have deep sympathy for Harry’s family.

“We have done and will continue to do everything we can to provide support and fight for justice for them.”