The Cabinet Office is understood to hold a number of text and email exchanges between Peter Mandelson and Morgan McSweeney, despite the theft of the former chief of staff’s phone in October last year.The whereabouts of McSweeney’s messages with Mandelson has been under intense scrutiny since it was reported his work device was stolen last year shortly after Mandelson was sacked as US ambassador.On Tuesday it was revealed that McSweeney did not disclose that he was Keir Starmer’s chief of staff when he reported the theft of his phone, according to a transcript released by the Metropolitan police in a highly unorthodox move for the force, which said it wanted to correct misreporting of the incident.But the Guardian understands that not all of McSweeney’s correspondence has been lost and a tranche is expected to be publicly released as part of the Mandelson files, expected in the coming weeks after the disclosure was forced by a parliamentary motion.It is understood that the Cabinet Office has retained some email and text messages between the pair, who had a close friendship.

McSweeney, who left the No 10 role in February, told police it was a government phone when he reported it had been snatched, minutes after the theft in central London.He told police the iPhone had a tracker on it, according to the transcript of the emergency call minutes after it happened.But he did not explain the sensitivity of the phone’s contents, records of the call suggest.On Tuesday, the Met released the full transcript of the 999 call made by McSweeney after the theft.The force said two attempts were made to follow up with McSweeney, who did not answer during office hours, and that CCTV cameras were examined, though at the wrong location.

Call handler Police, what’s your emergency?Morgan McSweeney Oh, hello, someone just robbed my phone …Call handler And where did this happen?McSweeney It happened in Belgrave Street in Westminster.[The Metropolitan police have subsequently said that the incident happened in Belgrave Road, Westminster, but that the call handler put in the address as Belgrave Road in Tower Hamlets.]Call handler And whose phone are you using now?McSweeney I’ve got two phones.I’m using my personal one.That was my work one.

..Call handler Have you got a tracker on the phone at all?McSweeney I do.It’s a government phone.Call handler And it’s your work phone.

What kind of phone is it?McSweeney It’s an iPhone.Call handler Do you know what model?McSweeney I don’t …Call handler Have you got any finance apps on the phone?McSweeney No.Call handler You’ll need to change any passwords for any logins you do have on the phone.McSweeney Yeah, OK.Call handler You’re not vulnerable in any way, are you?McSweeney No I’m not.

McSweeney’s phone records are subject to public scrutiny because of his correspondence with Peter Mandelson, who was sacked as the UK’s ambassador to the US over new revelations about his friendship with the late child sex offender Jeffrey Epstein.A Conservative motion passed in the Commons means the government is obliged to disclose all their correspondence.After the transcript was released, Downing Street said McSweeney had separately reported the theft to government security teams.Officials declined to confirm whether he had properly backed up or recorded his messages, saying they could not get ahead of the release of files concerning Mandelson’s appointment.The Met has admitted the wrong address was recorded for the theft, meaning that it was thought to have happened in a street in Tower Hamlets, rather than a Westminster street of the same name.

They conducted a review of any available CCTV cameras in the area where the incident was mistakenly believed to have happened, which did not identify any realistic lines of inquiry.Police are now revisiting the closed investigation into the theft.In the call, McSweeney says the phone is his work device and he has reported it to his office already to attempt to have it tracked.Though he says the phone is a “government phone”, he does not say there could be a higher risk because of his job.Starmer’s official spokesperson said “relevant government security teams” in Downing Street were notified the same day.

He refused to say whether those teams had tried to track or wipe the phone, saying only that there were “long-established and robust processes to manage information security”.Reports have said the lost phone meant some messages between McSweeney and Mandelson were lost.The spokesperson refused to say whether this was the case, while setting out that officials with government phones were obliged to record or back up relevant information such as WhatsApp messages.“Messages only need to be kept where they relate to substantive discussions or decisions that form part of the official record,” he said.“Significant government information exchanged via these channels must be captured into government systems by copying, forwarding, screenshotting or recording its substance.

”Individuals decided how the rules applied to each communication “using their professional judgment and considering the context”, he said.In the call transcript, McSweeney says the theft took place in Westminster.The call handler later refers to “Stepney Green park”, which is near the incorrect address, though McSweeney does not appear to recognise that.McSweeney says in the transcript that he is reporting the theft just minutes after it occurred.He says he attempted to follow the thief, but is told by the handler not to take any further risks.

He says he wishes to make a crime reference report immediately, rather than wait to be contacted by an officer.No 10 has said the device was shut off immediately and McSweeney was issued with a new device the next day with the same number.The WhatsApp messages of aides and ministers are due to be published in the next tranche of the Mandelson files and the prime minister is said to be braced for potential further resignations over their contents.McSweeney resigned in February over his role in Mandelson’s appointment as ambassador to the US.Thousands of documents in the second tranche of the Mandelson files – expected to include informal communications alongside formal messages like those in the first batch – are expected to be released after Easter.

A Met spokesperson said: “On Monday 20 October police received a report from a man in his 40s alleging that his phone had been snatched.“The incident was recorded as having taken place in Belgrave Street, E1.A review of the allegation, including a consideration of whether there was available CCTV, did not identify any realistic lines of inquiry.The investigation was subsequently closed.“In the course of responding to a recent media inquiry, we became aware that the address was entered incorrectly at the time of the initial call and should instead have been recorded as Belgrave Road, Pimlico.

Having identified this error, the report will be amended and the assessment of whether there is available evidence revisited.”