The US Department of State has said the decision to refuse an extradition request for Harry Dunn’s alleged killer was final, after an Interpol red notice was issued for her arrest. But the UK’s Labour party has signalled that they will be pressing for some form of parliamentary inquiry into the government’s “clear and repeated failings”. The teenage motorcyclist’s family were told by Northamptonshire police on Monday that 42-year-old Anne Sacoolas was “wanted internationally” in connection with his death. The US state department has already rejected a UK Home Office extradition request following the decision of the Crown Prosecution Service to charge her with causing death by dangerous driving. In an email to the 19-year-old’s parents, the Northamptonshire force said “the wanted circulations should be enacted” if Sacoolas left the US. But a state department spokeswoman insisted Sacoolas had diplomatic immunity from criminal jurisdiction. The spokeswoman said that granting the extradition request for Sacoolas would have rendered the invocation of diplomatic immunity “a practical nullity” and would have set an extraordinarily troubling precedent. She added that the decision of the US secretary of state, Mike Pompeo, to decline the UK’s request for extradition was final. The point is likely to be contested in a judicial review that is forcing the Foreign Office to reveal documents detailing its shifting position on whether Saccolas as a family member working at a US base in the UK enjoyed diplomatic immunity. The review, regardless of the judicial outcome, is likely to be deeply embarrassing to the Foreign Office. Lisa Nandy, the shadow foreign secretary, has taken up the issue since being given her portfolio and seems determined to try to uncover exactly how the Foreign Office handled the case in the fortnight after Dunn’s death in August last year. In a lengthy statement Nandy welcomed the move to apply an Interpol red notice to Saccoolas, saying: “This is an important first step in the journey to secure justice for Harry Dunn and his family. “It has been nine months since Harry lost his life and Ms Sacoolas left the UK without the permission of Northamptonshire police. The decision to issue this notice highlights the clear and repeated failings of the Foreign Office in the handling of the case. “It is now recognised that the decision to allow Ms Sacoolas to leave the UK – without the knowledge of the investigating police force – is a clear violation of legal protocol. It makes clear that Ms Sacoolas is wanted for crimes in the UK. Labour is working on a cross-party basis to establish a parliamentary inquiry into how this was allowed to happen and we will continue to raise this with the United States authorities. “The foreign secretary must now urgently come to the house to explain these failings, and set out how he will engage with his counterparts in the United States to resolve this situation and provide much-needed closure for Harry Dunn’s family and loved ones.” It is not clear what form any parliamentary inquiry could take. The Commons foreign affairs select committee already has six inquiries underway, and is meeting only once a fortnight at present. Much of its work is being conducted by correspondence, and at a truncated Foreign Office questions in the Commons this week the Dunn case was not mentioned. Responding to the accusations, a Foreign Office spokesman said: “We have deep sympathy for Harry’s family. “We are confident that we have acted properly and lawfully in relation to Harry’s death. We consistently called for Anne Sacoolas’s immunity to be waived before she left the UK. “Both the prime minister and the foreign secretary have been clear with the US that the refusal to extradite her amounts to a denial of justice, and that she should return to the UK.”