The American woman who fled the UK after teenager Harry Dunn was killed in a crash near a US military base has asked to be interviewed by British police officers in the United States under caution.
Northamptonshire chief constable Nick Adderley revealed the news as he urged Radd Seiger, who is acting as spokesman for the Dunn family, to "exercise constraint".
Anne Sacoolas, the wife of a US diplomat, is believed to have been driving on the wrong side of the road when she hit 19-year-old Harry's motorbike outside RAF Croughton in Northamptonshire on August 27. She later fled to the US, claiming diplomatic immunity.
Harry's parents Charlotte Charles and Tim Dunn have made repeated pleas for Mrs Sacoolas to return to the UK to "face justice" while Mr Seiger has accused the authorities of "further compounding the family's misery" through "contradictory" actions.
Speaking at a press conference yesterday, Mr Adderley said Mrs Sacoolas, was "utterly devastated" and had asked to be interviewed by UK police officers in the US.
"Lawyers have clearly stated that the suspect wants to be personally interviewed by officers from Northamptonshire Police in order for them to see her and the devastation this has caused her and her family," he said.
"We do understand from colleagues in the US that the family is utterly devastated."
He said the force was awaiting the necessary visas before officers could travel to the US but that the suspect, who he did not actually name, would be interviewed under caution.
Mr Adderley said: "From the police's point of view we have to make sure we maintain the integrity of all of the evidence and that it is not skewed by it (the diplomatic immunity debate) to ensure a fair trial should we get to an extradition position and she comes back to the UK."
Mr Adderley called on Mr Seiger to consider his behaviour.
"I urge the family spokesman to exercise constraint in his commentary as the case moves forward. I understand the emotion and I understand the anxiety," he said.
"I also understand the will and the want for answers.
"I have offered to go and see the family on two occasions now and on both occasions that has not been able to happen."
He said that was due to information being requested by Mr Seiger which police were unable to share for legal reasons.
He also denied the investigation had slowed down.