The ex-adviser from Downing Street, embroiled in a puzzling case of his stolen mobile phone, was discovered to have used two additional devices that might hold communications tied to Peter Mandelson’s role as US ambassador, according to insiders.

Morgan McSweeney faces mounting scrutiny to clarify the circumstances of the theft he reported last October. This occurred amid demands from MPs for transparency regarding correspondence potentially shedding light on why Lord Mandelson received the appointment, despite his ties to Jeffrey Epstein.

At that period, as the Conservatives planned to leverage a Commons procedure to compel the release of all messages concerning Mandelson’s appointment and subsequent resignation, Downing Street staffers convened to devise a strategy concerning ‘Morgan’s messages’.

Shortly thereafter, on October 20, McSweeney, then serving as the No 10 chief of staff, reported the theft of his official iPhone in London.

Following McSweeney’s report to Downing Street, the phone was remotely wiped to secure its data.

Recently, The Mail on Sunday has uncovered that McSweeney also owned two personal phones: one was shut down earlier this year, while the other remains operational.

Asked this weekend if all his phones had been searched for applicable messages, No 10 said that it was still in the process of asking ‘relevant individuals’ for messages relating to Lord Mandelson.

On Friday the Cabinet Office asked Lord Mandelson for the messages on his personal phone, two months after MPs demanded their publication.

The Mail on Sunday has established Morgan McSweeney (pictured) also possessed two private phones: one was deactivated earlier this year, while the other one is still in service

Mr McSweeney is under pressure to explain the full details of the theft he reported last October, when MPs were pushing for the disclosure of corresponence that could explain why Lord Mandelson (pictured) was given the job despite his connections with Jeffrey Epstein

Scotland Yard was forced to reopen the investigation into the reported theft last week after questions were raised over the sequence of events.

Detectives are examining CCTV footage from the street where Mr McSweeney claims he was robbed, and have asked him to provide a formal statement about the incident.

To add to the intrigue, a senior official in Boris Johnson’s government has said the messages on Mr McSweeney’s government phone should have been backed up.

Helen MacNamara, who was the Deputy Cabinet Secretary during the Covid pandemic, said: ‘It’s really simple. If it belongs to the Government and it’s the business of the State, the records should be kept. 

‘They can be kept on the phone, but then the things on the phone should be periodically transferred on to the official record. It’s not massively complicated.’

A call log published by Scotland Yard showed that Mr McSweeney told an officer that his phone had been snatched by a bike rider as he walked home from a restaurant in Pimlico, central London.

But he gave the police call handler the incorrect location, telling them he was in Belgrave Street, which is in east London, rather than Belgrave Road in Westminster.

As a result, Scotland Yard’s initial attempt to recover CCTV of the incident was doomed from the start.

Mr McSweeney also failed to tell the police that he worked at No 10, meaning the Yard did not realise that the device could contain sensitive material and contacts. He also gave his Scottish rather than his London address.

In addition, The Telegraph reported yesterday that Mr McSweeney failed to respond to police requests asking if he had managed to locate the missing phone using its inbuilt tracker.

Ministers fear that Mr McSweeney could be forced to appear before MPs to clear up the mysteries surrounding his relationship with Lord Mandelson, the messages that were exchanged and the phone theft.

It comes after Tory leader Kemi Badenoch hinted that she was ready to force another Commons vote to compel Mr McSweeney to give evidence to explain ‘exactly what happened and why Keir Starmer signed off on Peter Mandelson’s appointment despite the warnings’.

Mr McSweeney resigned last month over his role in the decision to appoint Lord Mandelson as the British Government’s representative in Washington.

A No 10 spokesman said: ‘All government departments, ministers and relevant individuals are in the process of being asked to provide information they hold.’