The family of Harry Dunn has filed a civil claim for damages against his alleged killer in the United States.
Anne Sacoolas, 43, was charged with causing the teenager's death by dangerous driving following a fatal road crash outside RAF Croughton in Northamptonshire on August 27 last year.
The announcement comes ahead of the family's meeting with the Director of Public Prosecutions amid discussions over potentially a trial in Sacoolas's absence.
The family's spokesman Radd Seiger said Mr Dunn's alleged killer had "inexplicably" made no attempt to "resolve the dispute without having to go to court".
Mr Seiger told the PA news agency the teenager's parents, Charlotte Charles and Tim Dunn, have now filed a civil complaint in a court in the state of Virginia.
The suspect claimed diplomatic immunity following the crash and was able to return to her home country, sparking an international controversy.
Dunn family fight for justice
Dunn family fight for justice
Undated family handout file photo of Harry Dunn. Harry Dunn's mother, Charlotte Charles, has marked the anniversary of her son's death by saying his name is "forever written into history" � and vowed to carry on his family's fight for justice.
Andrea Leadsom MP and Harry Dunn family spokesman Radd Seiger arrive to speak to the media in Brackley, Northamptonshire, where the MP called on Donald Trump to personally intervene to ensure suspect Anne Sacoolas faces trial over teenager Harry Dunn's death a year ago.
File photo dated 09/10/19 of Charlotte Charles, the mother of Harry Dunn, speaking to the media after leaving the Foreign and Commonwealth Office in London, where she met Foreign Secretary Dominic Raab. Harry Dunn's mother, Charlotte Charles, has marked the anniversary of her son's death by saying his name is "forever written into history" � and vowed to carry on his family's fight for justice.
Harry Dunn family spokesman Radd Seiger (left), Harry's mother Charlotte Charles (centre) and her partner Bruce Charles, speak with Andrea Leadsom MP (right) in Brackley, Northamptonshire, where the MP called on Donald Trump to personally intervene to ensure suspect Anne Sacoolas faces trial over teenager Harry Dunn's death a year ago.
File photo dated 20/12/19 of Harry Dunn's mother Charlotte Charles (centre) and stepfather Bruce Charles (left) outside the Ministry Of Justice in London after meeting with the Director of Public Prosecutions. Harry Dunn's mother, Charlotte Charles, has marked the anniversary of her son's death by saying his name is "forever written into history" � and vowed to carry on his family's fight for justice.
File photo dated 15/10/19 of the entrance to RAF Croughton, in Northamptonshire, near where Harry Dunn, 19, died when his motorbike was involved in a head-on collision in August last year. One year on from his death, the family of Harry Dunn continue to fight for justice in a case which has sparked diplomatic tensions between Washington and London.
File photo dated 23/04/20 of US President Donald Trump, who was told to "reconsider its position" on the immunity given to 42-year-old suspect Anne Sacoolas, following a road crash outside a US military base in Northamptonshire which resulted in teenage motorcyclist Harry Dunn's death. One year on from his death, the family of Harry Dunn continue to fight for justice in a case which has sparked diplomatic tensions between Washington and London.
Tim Dunn (far right) and his wife Tracey Dunn (second right), as they gather with friends and family at Portland Bill to scatter his son's ashes in his favourite place in Weymouth, Dorset, a month before the anniversary of his death.
File photo dated 20/12/19 of the family of Harry Dunn (left to right) mother Charlotte Charles, stepfather Bruce Charles, family spokesman Radd Seiger and father Tim Dunn. Harry Dunn's parents have dropped their legal claim against Northamptonshire Police after concluding the force are "absolved of any blame" following their son's death.
Harry Dunn's mother Charlotte Charles arrives at the Foreign and Commonwealth Office in Westminster, London, for a meeting with Foreign Secretary Dominic Raab.
Cardboard cutout of Northampton Town fan Harry Dunn who died in a car crash last August is seen in the stands during the Sky Bet League Two play-off semi final first leg match at the PTS Academy Stadium, Northampton.
Business Secretary Andrea Leadsom and Harry Dunn's mother Charlotte Charles outside South Northamptonshire Council offices in Towcester, after they met following the news that the US have refused to extradite Anne Sacoolas who is charged with causing his death in a road collision outside RAF Croughton in August last year.
A motorbike convoy makes it's way through the village of Charlton after following Harry Dunn's last ride as a tribute to the teenager who died when his motorbike was involved in a head-on collision near RAF Croughton, in Northamptonshire in August.
Charlotte Charles (left), the mother of Harry Dunn, Bruce Charles, and Tracey Dunn speak to media after a motorbike convoy followed Harry Dunn's last ride through Brackley as a tribute to the teenager who died when his motorbike was involved in a head-on collision near RAF Croughton, Northamptonshire, in August.
Chief Constable of Northamptonshire Police, Nick Adderley (centre) and Superintendent Sarah Johnson speaking during a press conference at Northamptonshire Police HQ at Wootton Hall Park, Northampton about the death of Harry Dunn.
Harry Dunn's Auntie Katie Grant (right) and Nicola Watson tie a Green Ribbons which are being made be members of the village of Charlton, Oxfordshire in memory of 19-year-old Harry Dunn who died while out riding his Green motorcycle near RAF Croughton.
Please Drive on Left signs and arrows have been placed on the B4031 road outside RAF Croughton, in Northamptonshire, where Harry Dunn, 19, died when his motorbike was involved in a head-on collision in August.
(Left to right) Bruce Charles and Charlotte Charles (Harry's mother), lawyer Radd Seiger, Tim Dunn (Harry's father) and Tracey Dunn at a press conference at the Parker New York Hotel in New York, US, where Charlotte Charles said that Anne Sacoolas, the American woman suspected of causing her son's death, should be brought back to the UK to face justice.
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She was charged by the Crown Prosecution Service in December but an extradition request submitted by the Home Office was rejected by the US State Department the following month.
Speaking ahead of the meeting with Max Hill QC, Mr Seiger told PA: "Ever since Harry's family launched their campaign for justice last October, they have tried their level best to avoid any dispute with either Mrs Sacoolas herself, or the British or US governments.
"They came up against a brick wall at every turn and felt that they had no choice other than to launch their campaign.
"It remains the intention of the British authorities for Mrs Sacoolas to return to face the legal system in Britain and that is what she must do, self-evidently."
Mr Seiger continued: "Harry's parents are entitled to bring a claim for civil damages for Harry's wrongful death in the US courts in Virginia.
"They have sought to avoid a formal dispute with Mrs Sacoolas so as not to put the parents through any additional unnecessary stress.
"Inexplicably, there has been a total failure on Mrs Sacoolas's part to enter into the spirit of attempting to resolve the dispute without having to go to court.
"The parents have therefore, yet again, been forced to take yet another battle on since Harry's death and have today filed a formal complaint against Mrs Sacoolas in the Virginia court."
He added: "The parents wanted none of this. They have worked hard to avoid this. Mrs Sacoolas and her advisers clearly do not consider the further misery this imposes on Harry's family.
"They have already been through so much; however, they are more than capable of taking this battle on.
"However, right-minded people on both sides of the Atlantic will rightly be appalled and horrified."