Harry Dunn’s family are set to meet the shadow foreign secretary to encourage parliamentary scrutiny over the Foreign Office’s (FCO) handling of the case.

Family spokesman Radd Seiger said they will have a virtual meeting with Lisa Nandy on Friday to “discuss and agree next steps”.

The FCO has recently come under scrutiny after documents showed that a senior diplomat had sent a text message to their US Embassy counterpart saying they should “feel able” to put suspect Anne Sacoolas on the next flight home.

Initial disclosure documents, which surfaced earlier this year, showed a briefing note copied to Dominic Raab’s private secretary from three days after the crash in which the 19-year-old motorcyclist was killed – which revealed concern for some “very unpalatable headlines”.

A witness statement from the senior investigating officer at Northamptonshire Police said a Foreign Office official had requested the force delay telling the family that a waiver for Mrs Sacoolas’s diplomatic immunity had been declined by the US – adding that it would help if they could get their “ducks in a row” beforehand.

It is understood the FCO is confident officials acted lawfully and properly throughout the investigation.

Further disclosure documents are expected to be with Mr Dunn’s family in the course of this week.

The teenager was killed when his motorbike collided with a car outside a US military base in Northamptonshire in August last year.

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

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.

Speaking ahead of the meeting with Ms Nandy, Mr Seiger told the PA news agency: “The FCO did their level best to sweep everything under the carpet, hoping against hope that there would not be any ‘unpalatable headlines’, as they put it themselves.

“The whole thing stinks to high heaven.

“It is for the Opposition to hold the UK Government to account and to scrutinise their work.”

He continued: “Lisa Nandy has recently called for a parliamentary inquiry into the matter. We are grateful to her for carving out the time to meet with us.

“We intend to discuss and agree next steps with her.

“At the very least, senior ministers in the Government have serious questions to answer and if it is proven that there has been misconduct, we will ensure that those responsible are held to account to the fullest extent permissible.

“The Opposition will have an important role to play in the search for the truth.”