The Archbishop of Canterbury has added his voice to the calls for the woman who has admitted causing Harry Dunn's death to come back to the UK to face justice.
In October, Justin Welby wrote to the US ambassador in London urging them to reconsider the diplomatic immunity given to Anne Sacoolas after the fatal crash in Northamptonshire.
It is understood the principal leader of the Church of England yet to receive a reply from Robert Wood Johnson but Harry's family has thanked him for his support.
"@JustinWelby thank you for your support and involvement in aid of our campaign, we're extremely grateful #justice4harry #greenribboncampaign," the Justice4Harry Twitter account posted.
Harry's family continues to fight for answers as Mrs Sacoolas remains in the US despite admitting to being on the wrong side of the road before the accident outside Croughton in August.
The woman, thought to be married to a spy who was based at RAF Croughton, has been interviewed by Northamptonshire Police officers and the Crown Prosecution Service is yet to announce its decision on whether any prosecution will be brought forward.
The family, who live in Charlton and Brackley, fear the British government is delaying that decision, which the Foreign and Commonwealth Office (FCO) denies.
Nevertheless an application has been made for a judicial review into the FCO's handling of the case.
Mr Welby sent his letter to the ambassador on October 8, before Mrs Sacoolas had agreed to be questioned by British officers in the US.
A spokesman for the bishop told the MailOnline: "The archbishop has written to the US ambassador Robert Wood Johnson asking him to reconsider the diplomatic immunity.
"He would like Mrs Sacoolas to return so a full and proper investigation can be carried out."
Mr Welby has been contacted for comment.