The home secretary has been asked to consider a “virtual trial” for Harry Dunn death suspect Anne Sacoolas.
The American was charged with causing death by dangerous driving after a crash in August last year which resulted in the 19-year-old’s death.
The 42-year-old claimed diplomatic immunity following the collision outside RAF Croughton in Northamptonshire.
She was able to return to her home country, sparking controversy.
In a letter to Priti Patel on Monday, seen by the PA news agency, the Dunn family’s constituency MP Andrea Leadsom suggested “the possibility of the trial of Anne Sacoolas virtually or in her absence”.
The MP described it as a “way to achieve closure… without undermining the US decision not to accept the extradition request”.
“She could remain on US soil, have a virtual trial with a UK court, and should there be a custodial sentence, she could serve it in the US under the existing prisoner transfer agreement,” Ms Leadsom added.
She also wrote to the Solicitor General, the foreign secretary, the Crown Prosecution Service and the Lord Chancellor to put forward the idea.
Mr Dunn’s family said their “final goodbye” to their son last month as they scattered his ashes in his favourite place – Portland Bill, near Weymouth in Dorset.
Reacting to the letters, Mr Dunn’s mother Charlotte Charles, said: “For me and my family, it is all about doing the right thing and ensuring justice is done.”
The Home Office has been approached for comment.
A spokeswoman for the Attorney General’s Office confirmed a letter had been received but declined to comment further.
A Home Office extradition request was refused by US secretary of state Mike Pompeo in January.