The family of a motorcyclist killed in a crash involving the wife of an American diplomat have announced they are planning to sue US President Donald Trump's administration over an alleged cover-up. Harry Dunn, 19, died on August 27 when his motorbike and a car driving on the wrong side of the road collided.In a statement issued through her lawyers and reported in US media, Anne Sacoolas admitted she was driving. She left Britain claiming diplomatic immunity before she was interviewed by police.Dunn's parents, Charlotte Charles and Tim Dunn, have urged US President Donald Trump's administration to extradite Sacoolas to Britain, to no avail. "We are bringing claims against both Mrs Sacoolas in the USA for civil damages as well as the Trump administration for their lawless misconduct and attempt to cover that up," family spokesperson Radd Seiger said. "The Trump administration is not only hellbent on breaking international laws, rules and conventions on diplomatic immunity," he added, "but they have no care or concern for the welfare of Harry's family or any real intent on finding a solution".The accident took place near a British airbase used by the US military as a communications hub and where 42-year-old Sacoolas's husband was stationed.The case, which has generated huge public interest in Britain, has fueled tensions between London and Washington. Trump called the crash a "terrible accident", saying it was common for Americans in Britain to have a hard time driving on the left side of the road. Dunn's parents visited the White House October 15. They called Trump warm and welcoming but criticised the White House's attempts to engineer a snap meeting with Sacoolas, who was in a room next door with photographers. Tim Dunn told Sky News the family were "disgusted" and "appalled" at the suspect's behaviour. "I'm angry that someone could do this and then get on a plane and go," he said.The family has already filed a lawsuit against the British government for letting Sacoolas leave the country in the first place. British police announced last week that investigators will travel to the US to interview Sacoolas.