Rishi Sunak faced calls to launch an inquiry after one of his protection officers was arrested over alleged bets on the timing of the General Election.
The Metropolitan Police said it was informed by the Gambling Commission that a police constable from the force’s Royalty and Specialist Protection Command was being investigated over the alleged bets.
The Gambling Commission is leading an investigation into alleged betting offences, which has reportedly been extended to include a second Conservative candidate.
It emerged last week that Craig Williams, who served as Mr Sunak’s parliamentary private secretary and is the Conservative candidate for Montgomeryshire and Glyndwr, was under investigation after he “put a flutter” on when the election would take place.
On Wednesday evening, the BBC reported a second Conservative candidate was being examined by the Gambling Commission over an alleged bet also connected to the timing of the election.
A Conservative Party spokesman told the BBC: “We have been contacted by the Gambling Commission about a small number of individuals. As the Gambling Commission is an independent body, it wouldn’t be proper to comment further, until any process is concluded.”
The candidate has been approached for comment by the PA news agency.
Liberal Democrats deputy leader Daisy Cooper, responding to news of the police officer’s arrest, said: “Rishi Sunak must call a Cabinet Office inquiry into what is shaping up to be yet another scandal at the heart of Government.
“This stinks of yet more sleaze and answers are needed. An inquiry is needed to understand who knew what and when.”
The officer, who has been removed from operational duties, was bailed pending further inquiries after they were taken into custody on Monday on suspicion of misconduct in a public office, according to the Met.
The matter has been referred to the Independent Office for Police Conduct (IOPC), which said it will “make a decision on the level of IOPC involvement in due course.”
According to the Crown Prosecution Service’s website, misconduct in a public office “concerns serious wilful abuse or neglect of the power or responsibilities”.
Those who can be accused of the offence include judges, bishops, MPs, civil servants, army officers, prison staff and police constables.
The Gambling Commission said in response to the officer’s arrest: “Currently the commission is investigating the possibility of offences concerning the date of the election.
“This is an ongoing investigation, and the commission cannot provide any further details at this time.”
Mr Sunak previously said it was “very disappointing” that Mr Williams had allegedly placed a bet on the date of the General Election.
Mr Williams, who was the Tory MP for Montgomery until the election was called, is alleged to have placed a £100 bet on a July polling day some three days before Mr Sunak named the date as July 4, at a Ladbrokes in his constituency.
He previously said he had clearly made a “huge error of judgment” but refused to say whether he placed a bet on the basis of insider information.
Elsewhere on Thursday, Mr Sunak will join three other party leaders in taking part in a BBC Question Time special.
The two-hour programme will see each leader appear one by one to face questions from the audience.
Labour’s Sir Keir Starmer will also take part along with Scotland’s First Minister John Swinney for the SNP and Sir Ed Davey for the Liberal Democrats.
The latest televised election event comes after YouGov said the Conservatives are projected to slump to their “lowest seat tally in the party’s almost 200-year history” at the election.
YouGov said its latest study projects Labour to secure 425 seats, the Tories 108, the Liberal Democrats 67, SNP 20, Reform UK five, Plaid Cymru four and the Green Party two.
It noted such a scenario would hand Labour leader Sir Keir Starmer a 200-seat majority while it added Reform UK leader Nigel Farage is “likely” to win in Clacton.
YouGov used a technique known as multi-level regression and post-stratification (MRP) to model the outcome of the election in every constituency across Britain.
It said the estimated seat projections were based on modelled responses from 36,161 adults in England and Wales and 3,818 in Scotland between June 11 and 18.
Housing policy will also be a focus on Thursday, with Communities Secretary Michael Gove leading the attack on Labour’s approach to the issue.
The Tories claim that Labour not matching their commitments will amount to a “first-time buyer tax” for those trying to get on the property ladder.
Labour countered by saying: “This reeks of desperation from the Tories.”
The party added that it intends to “get Britain building” and help working families onto the housing ladder.
The Lib Dems will warn about the “pothole postcode lottery”, as they insist £300 million should be spent over the next parliament to fill 1.2 million potholes a year.