Michael Forsyth, the Lord Speaker of the House of Lords, was named in reports as having warned the police that Lord Mandelson was going to flee to the British Virgin Islands.
It was actually Sir Lindsay Hoyle, the speaker of the House of Commons, who had.
Lord Mandelson was arrested on Monday on suspicion of misconduct in public office, regarding his time as business secretary in Gordon Brown's cabinet in the 2000s.
He went with police from his home in Camden, north London, at about 4.15pm on Monday to a police station, where he was questioned for eight hours before being released on bail just after 1am.
Lord Mandelson was seen on Thursday for the first time since returning home from his arrest, appearing stony-faced as he left his house just after 1pm and returned at about 4pm.
The former Labour peer denies any wrongdoing.
It emerged on Tuesday that he was arrested because police had been told he was a flight risk.
However, the wrong Speaker was named as the source of the claim.
After Lord Forsyth was named, Sir Lindsay Hoyle, the House of Commons Speaker, told MPs on Wednesday morning it was actually he who had warned the police after he was passed the information while he was on holiday in the British Virgin Islands last week.
The Met apologised to Sir Lindsay on Wednesday, saying it had "inadvertently" revealed information about why Lord Mandelson had been taken into custody.
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Now, the force has apologised to Lord Forsyth as well.
A spokesperson said on Thursday: "The Met has also apologised to the Speaker of the House of Lords, following the inadvertent revealing of information into allegations of misconduct in public office."
Lawyers for Lord Mandelson denied the "baseless" allegation that he was going to flee, and said he had already agreed to attend a voluntary interview in a fortnight's time.
They have also asked the Met for the "evidence relied upon to justify the arrest".
Lord Mandelson was sacked as British ambassador to the US in September after it emerged he remained in close contact with billionaire Jeffrey Epstein after his conviction for paedophilia.
Sir Keir Starmer has said the former minister lied to him as part of the vetting process.
At the beginning of this month, the US Department of Justice released another tranche of Epstein emails, which revealed how close their relationship was.
Lord Mandelson resigned from the Labour Party to avoid causing "further embarrassment", then stepped down from the House of Lords - but he remains a Lord in name as peerages can only be taken away through an Act of Parliament.
The Labour chief whip in the Lords, Roy Kennedy, said this week that the government would not give the Terminally Ill Adults (End of Life) Bill more time before the May deadline, when all legislation must have passed or automatically falls.
The team behind the bill also confirmed they now expected the legislation in its current form to fail.
There are six remaining sitting days left before May, when the King's Speech happens, and the government is not repeating what it did in December by giving more time.
Advocates for the bill did not blame the government, which it said had been helpful to date, and instead aimed their fire on a minority of peers who have been asking thousands of questions about the details of the bill.
Broadcaster and campaigner Esther Rantzen told Sky News: "This is absolute blatant sabotage. This is a handful of peers putting down 1,200 amendments not to scrutinise the bill, which is their job, but to block it.
"A few peers for their own reasons have decided that they're going to stop this going through parliament, and the only way to stop them would be to invoke the Parliament Act, which has happened before, or get rid of the House of Lords - they're clearly not fit for purpose."
She said she was still hopeful the change would come, as there is a rising cry for reform all around the world. She paid tribute to Sir Keir Starmer, who favours a change in the law, and said he had done everything he promised her before the election.
Frank Sutton, who has terminal cancer and wants to choose how she dies, told Sky News: "I don't want to die without dignity, without it being my choice, without my family knowing that this is what I want."
Dr Gordon McDonald, chief executive of Care Not Killing, which is opposed to assisted dying, told Sky News: "This issue is very difficult, and it needs proper scrutiny - that's what the members of the House of Lords have been doing.
"It didn't get proper scrutiny in the House of Commons. It's right that parliaments look at these bills properly and give them due consideration, that's what the House of Lords is doing."
Many members of the public and even MPs were unaware that the bill was likely to fail. Earlier this week, the Welsh Parliament approved a "legislative consent order", endorsing in theory the legislation that it expected to come out of Parliament.
The debate will now focus on what happens after May, with proponents of a change in the law saying the public polling and the repeated backing of MPs means that this legislation should be given a second chance.
However, the government is likely to continue keeping the issue at arms length, since there is no single cabinet position on the issue and members of the cabinet like Wes Streeting and Shabana Mahmood are implacably hostile to the change. This makes a change in the law much more tricky.
Some MPs who backed the bill in its Commons stages have told Sky News the process was so torturous that they would not want a repeat of it. Supporters have suggested that you would not have to go through the entire process - avoiding committee stage if the same bill was resurrected - and the Commons stages could in theory be done in one day, and the Parliament Act then deployed to override the objections in the Lords.
However, the more turbulent political context for the government, the bandwidth that even this would occupy in government, and the fact the reforms would not be complete before a general election, mean that this would be a significantly bigger challenge second time around.
Derby Crown Court heard Jack Bentley, 30, from Meadow Way, Derby, was seen veering into the grass verge of the A50 in Derbyshire, swerving between lanes and lane hogging on 6 April 2025.
His Ford Focus then collided into the back of a Nissan X Trail, which was queuing in stationary traffic.
A pregnant passenger in the Nissan suffered a fractured pelvis, was rushed to hospital and gave birth prematurely, leaving her baby in intensive care, the court was told.
The Nissan's driver and two other children were also injured, while the family's pet dog had to undergo emergency surgery.
Bentley admitted two counts of causing serious injury by dangerous driving and, on 11 February, was jailed for two years and four months.
In a victim impact statement, the woman said she found the emergency caesarean "very traumatic" and "missed out on so much in those early moments" following the birth because her baby was in an incubator.
She added: "I remember being there watching when all the nurses and doctors rushed around because her lung had collapsed and I had to lay there scared for her. Hours later, the other lung also collapsed.
"She wasn't strong enough for the world yet. For my first pregnancy, this was a very traumatic experience and one no parent expects or wants to experience."
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Dashcam footage from another motorist captured the crash, as Bentley's Ford Focus continued moving at speed towards the stationary line of vehicles, then collided into the rear of the Nissan, causing debris to fly into the air and scatter across the road.
After Bentley's arrest at the scene, analysis of his phone data showed he had been using his phone while driving, visiting online gambling sites as he travelled from Blackpool to Derby.
PC Richard Morris, who led the investigation, said: "This was an appalling display of driving by Bentley, who spent the majority of his journey distracted by being on his phone.
"From watching the dashcam footage, it was clear that had he been paying attention he would have seen the queue of traffic in front of him and been able to stop in time.
"I know that the physical, mental and emotional trauma from this incident continues to impact on this family."
Bentley was also disqualified from driving for three years and two months.
The court may have delivered justice in a case such as Ian Huntley's, but for some fellow criminals, what's really needed is revenge - to make you suffer like you made your victims suffer.
From his first day in inside, there was a price on Huntley's head - not a monetary one, but the promise of "respect" for anyone who attacked him.
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In the violent world of a top security jail, respect from your fellow cons is everything and there's nothing quite like hurting a prisoner considered "the lowest of the low".
An infamous villain once described to me over lunch how he witnessed a planned prison knife attack on a child sex offender, a story he told years later with relish, laughter and no grim detail spared.
Huntley would have been on Rule 43, held in the prison's unit for vulnerable inmates, mostly sex offenders, but police informants too.
But it's impossible to fully protect everyone, especially in today's chaotic jail system with overcrowding and increased violence, alongside the regular departure of disillusioned older warders who are replaced with more inexperienced officers.
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Mark Leech, editor of the Prisons Handbook, said: "The upcoming young thugs in prison see people like Huntley as a way of gaining kudos, especially if they are already serving lengthy sentences."
If Huntley recovers, he will always be vulnerable to another attack.
Some prisoners have long memories and plenty of time to think.
Some families said that baby deaths were being misclassified to prevent further investigation.
Baroness Amos, who is leading a national investigation into maternity care, said: "Maternity and neonatal services in England are failing too many women, babies, families, and staff."
Investigators spoke to hundreds of harmed families and staff across 12 NHS trusts in England, many of whom shared shocking accounts of their experiences.
Have you been affected by poor maternity care? Email maternitystories@sky.uk
Some families alleged in the report that their babies were designated stillborn instead of dying after birth.
"They felt the system incentivised the recording of deaths as stillbirths as this prevents the case from being investigated by a coroner," the report said.
Jack and Sarah Hawkins, whose daughter Harriet was stillborn, were not part of the Amos investigation, but have fought to get a separate inquiry launched for bereaved and harmed families in Nottingham.
Jack said: "We have met a number of people and heard reports from a number of people whose babies they say were born alive and who the hospital say were born dead.
"And that is a horrific position, a horrific thing to say, and yet of course we believe the victims, not the NHS, who have shown themselves to be sparing with the truth around some of these issues."
Neither supported Baroness Amos' inquiry. Sarah said it "isn't going to change anything".
'There needs to be a public inquiry'
"Families just want accountability and this report is not going to bring accountability," she said.
"There needs to be a statutory public inquiry and some form of justice. Because if your child died in any other circumstance in life, you would get justice. People would be held to account.
"Yet in maternity services, it doesn't happen like that and that is so unfair."
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The National Maternity and Neonatal Investigation (NMNI) in England was set up by Health Secretary Wes Streeting in June after he met families harmed by poor maternity care.
In her initial report released in December, Ms Amos said "nothing prepared her" for the amount of "unacceptable care" families currently receive.
Investigators have met more than 400 family members and heard from over 8,000 people, including NHS staff.
NHS England has been contacted for comment.