The family of Harry Dunn and alleged victims of billionaire paedophile Jeffrey Epstein have joined forces to put pressure on Anne Sacoolas and the Duke of York to "co-operate with law enforcement".
Radd Seiger, spokesman for Mr Dunn's family, reached out to Lisa Bloom,the lawyer representing six of Epstein's alleged victims, saying there was a "common thread" in both cases.
In a press conference on Wednesday, Ms Bloom said the "parallels between the two cases are eerie" and involved "everyday teenagers" who were "victimised".
Mr Seiger said it was "terrible advice" for Mrs Sacoolas and the duke if they are being advised "it's all going to go away" and they should just "wait it out".
The pair joined forces to call for both Mrs Sacoolas to return to the UK and Andrew to face questioning from the FBI in the US.
Mrs Sacoolas 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 the 42-year-old last month.
The 19-year-old was killed when his motorbike crashed into a car outside US military base RAF Croughton in Northamptonshire on August 27 last year.
Mrs Sacoolas claimed diplomatic immunity following the crash and was able to return to her home country, sparking an international controversy.
Allegations about Andrew have also surfaced in recent weeks by Virginia Giuffre, who claims she was trafficked by Jeffrey Epstein and alleges the duke slept with her on three separate occasions, including when she was 17 – still a minor under US law.
Andrew strenuously denies the allegations.
In an interview with BBC Panorama, Ms Giuffre told how she was left "horrified and ashamed" after an alleged sexual encounter with Andrew in London in 2001.
She claimed she danced with him in Tramp nightclub, adding he was "the most hideous dancer I've ever seen in my life" and "his sweat was ... raining basically everywhere".
During a Newsnight interview, the duke said the alleged encounter in 2001 did not happen as he spent the day with his daughter, Princess Beatrice, taking her to Pizza Express in Woking for a party.
He also said he does not recall meeting Ms Giuffre, and had a medical condition at the time, after suffering an overdose of adrenaline in the Falklands War when he was shot at, that meant he did not sweat.
At the press conference in New York, Ms Bloom said: "Today we stand with the family of Harry Dunn and they stand with us. Both Mrs Sacoolas and Prince Andrew must co-operate with law enforcement.
"I call upon my government, the US, to return Mrs Sacoolas to the UK to face justice."
The lawyer said Andrew needs to "answer questions about Jeffrey Epstein and his own behaviour", adding: "In both countries everyone is equal in the eyes of the law."
Speaking of the reasons for reaching out to Ms Bloom, Mr Seiger said: "It's about evasion of justice.
"These are the two greatest allies in the world and they follow a rules-based system. No-one, no matter who you are ... is above the law.
"We all break the rules from time to time but we don't get to walk away and hide."
He said after meeting Kiki, an alleged victim of Epstein also present at the press conference, "what you see every day is a strengthening and stiffening of resolve".
In a message to Andrew, Mr Seiger said: "If you have nothing to hide get on a plane and meet with Kiki, and help her and help other victims ... there's no other way"
Asked by a reporter if the pair are proposing a "swap", Mr Seiger said: "It can never be a swap but at the heart of extradition treaties is reciprocity.
"If you want me as a nation to send people you want to prosecute, you have to agree to do the same thing.
"It can never be a straight swap but be careful what you wish for.
"If you want people from the UK like Prince Andrew, Julian Assange ... you have to think about making sure that treaty is followed to the letter."
He said the US government's decision to refuse to extradite Mrs Sacoolas was "legally indefensible" and "effectively ripping up the treaty".