The Metropolitan Police is speaking to Cabinet Office officials as the force continues its investigation into Morgan McSweeney's missing phone, it is understood.
Scotland Yard officers are believed to have been in contact with civil servants to confirm details of the stolen work device of the Prime Minister's former chief of staff.
It comes amid reports that the phone's tracking data was lost when Downing Street wiped the phone after Mr McSweeney was mugged in October last year.
Mr McSweeney quit No10 in February this year as he took responsibility for advising Keir Starmer to name Peter Mandelson as Britain's ambassador to the US.
His resignation came days after MPs demanded the publication of all files related to the disgraced peer's appointment to the senior diplomatic role.
The scope of the 'humble address' motion could have included messages exchanged between Mr McSweeney and his long-time friend Lord Mandelson.
But it has since been revealed that Mr McSweeney's phone was stolen on 20 October 2025 and was not backed up, leading to concerns about the loss of correspondence.
Tory leader Kemi Badenoch has suggested 'something fishy' is going on, but Sir Keir has called it 'far-fetched' to link the theft to the release of files about Lord Mandelson.
The Metropolitan Police is speaking to Cabinet Office officials as the force continues its investigation into Morgan McSweeney's missing phone, it is understood
MPs on the House of Commons' Foreign Affairs Committee are due to hear evidence from Mr McSweeney about Lord Mandelson's appointment as Britain's ambassador to the US
Mr McSweeney is said to have first called his office in Downing Street before calling the police when his phone was snatched out of his hand by a man on an e-bike.
According to The Telegraph, Mr McSweeney asked No 10 officials for the tracking location so he could try to retrieve the device himself.
But Downing Street's security team are said to have instead remotely shut off the device, immediately removing all of its data, so that the thief could not access it.
The newspaper reported that the phone tracking data was lost when No 10 wiped the phone.
Scotland Yard initially wrongly recorded the theft as having taken place in east London rather than Westminster.
This came after Mr McSweeney wrongly gave his location as Belgrave Street rather than Belgrave Road during the October 20 call.
This meant officers checked the wrong CCTV and concluded there were no realistic lines of inquiry to follow - a decision which has since been reviewed.
Scotland Yard said last month it was taking a fresh look at its assessment of whether there is available evidence.
MPs on the House of Commons' Foreign Affairs Committee are due to hear evidence from Mr McSweeney tomorrow about Lord Mandelson's appointment.
He has denied claims he bullied civil servants into naming Lord Mandelson as the UK's top diplomat in Washington DC.
It comes after ex-Foreign Office chief Sir Olly Robbins said there was an 'atmosphere of pressure' and 'constant chasing' from No10 about Lord Mandelson's vetting.
Downing Street has also denied that civil servants were bullied or cajoled by Mr McSweeney.