Prime Minister Rishi Sunak faced calls on Thursday to launch an inquiry after one of his close protection officers was arrested for allegedly betting on the timing of the UK general election.
London's Metropolitan Police said it was told by the Gambling Commission that an officer working for the prime minister's security detail was being investigated over the alleged bets.
The regulator had already been looking into claims that a Conservative party candidate who served as Sunak's ministerial aide placed a bet on when the election would be held.
A second candidate from Sunak's party is now also under investigation about an alleged bet on the date of the poll, the BBC reported on Wednesday evening.
The Conservative party confirmed to the broadcaster that the commission had contacted it about "a small number of individuals", without commenting further.
Senior minister Michael Gove told the BBC on Thursday: "If people have used inside information to place bets, that is deeply wrong."
The deputy leader of the smaller opposition Liberal Democrats, Daisy Cooper, urged Sunak to order an inquiry.
"This stinks of yet more sleaze and answers are needed. An inquiry is needed to understand who knew what and when," she added.
Sunak announced that a general election would be held on July 4, taking his own party by surprise as he still had six months to call a vote.
The Tories are expected to be dumped out of office after 14 years in office, with polls consistently putting the main opposition Labour party some 20 points ahead.
As well as criticism of Sunak's decision to go early, the Tory campaign has been widely criticised for a series of gaffes, including a photocall in Belfast near where the doomed Titanic was built.
Sunak's own already dire personal ratings were also hit after he left an international event to mark the 80th anniversary of D-Day early.
The Met said the officer, a member of the force's Royalty and Specialist Protection Command, was no longer on operational duties.
The officer was taken into custody on Monday on suspicion of misconduct in a public office, then released on bail pending further inquiries.
A referral has been made to the Independent Office for Police Conduct, the watchdog confirmed. (AFP)
Lord Karan Bilimoria speaks during the event
