Former British ambassador to the US Peter Mandelson has been released on bail after his arrest on suspicion of misconduct in public office.
The former Labour minister has been accused of passing sensitive information onto paedophile financier Jeffrey Epstein during his time as business secretary.
In a statement issued just after 2am, a spokesperson for the Metropolitan Police said: "A 72-year-old man arrested on suspicion of misconduct in public office has been released on bail pending further investigation.
Mandelson returns home after released on bail
"He was arrested at an address in Camden on Monday, 23 February and was taken to a London police station for an interview.
"This follows search warrants at two addresses in the Wiltshire and Camden areas.
"We are not able to provide further information at this stage to prevent prejudicing the integrity of the investigation."
UK Prime Minister Keir Starmer is due to chair his cabinet today.
The Liberal Democrats will, meanwhile, seek to force the public release of files relating to Andrew Mountbatten-Windsor's appointment as a trade envoy, as the former prince also faces accusations of sharing sensitive information with Epstein while in the role.
Footage yesterday showed Mr Mandelson being led out of his house by a plain-clothes police officer.
Two of his properties were previously searched by police in connection with the allegations, which surfaced following the US Department of Justice's document dump related to Epstein last month.
As part of the so-called Epstein files, emails from 2009 appear to show Mr Mandelson passed on an assessment by former prime minister Gordon Brown's adviser of potential policy measures including an "asset sales plan".
He also appeared to discuss a tax on bankers' bonuses and confirmed an imminent eurozone bail-out package the day before it was announced in 2010.
The emails appeared to be sent to Epstein after he was convicted of sex offences.
It is understood the Crown Prosecution Service is yet to offer any early investigative advice in relation to the allegations against Mr Mandelson.
The Cabinet Office previously referred material to police in connection with the probe into Mr Mandelson after an initial review of the Epstein files suggested "safeguards were compromised".
The arrest came shortly after MPs were told the first tranche of documents related to Mr Mandelson's appointment as US ambassador is expected to be released in early March.
Chief Secretary to the British Prime Minister Darren Jones said some of the correspondence between Downing Street and the peer will be delayed "because of the Metropolitan Police interest".
Mr Starmer previously said the files will prove Mr Mandelson lied during the vetting process before taking on the ambassador role.
Following the release of the Epstein files, Mr Mandelson said he has "no recollection" of receiving payments totalling $75,000 from Epstein between 2003 and 2004, as bank details in the documents indicated.
Epstein is also said to have paid for an osteopathy course for Mr Mandelson's husband, Reinaldo Avila Da Silva, in 2009, at the time the government was dealing with the financial crisis.
Mr Mandelson's arrest comes days after the former prince was taken into custody on suspicion of misconduct in public office.
Mr Mountbatten-Windsor was released under investigation.
Despite being stripped of his title last year, the former duke of York is still eighth in line to the throne, and an Act of Parliament would be required to remove and prevent him from ever becoming king.
The UK government will consider introducing such legislation once police have finished their investigation into the King's disgraced brother, it is understood.
The Lib Dems will table a humble address in the Commons - the same mechanism the Tories used to press for the release of files on Mr Mandelson's appointment as ambassador - in a bid to compel the government to disclose information about Mr Mountbatten-Windsor, who served as a trade envoy between 2001 and 2011.
