Five Conservatives have been implicated in the scandal, including two candidates who have been suspended from the party. There is no suggestion that any of them have broken the criminal law.
However, the Met’s involvement raises the possibility that any new inquiries could involve politicians being investigated for potential public office offences.
But a senior police officer working in Rishi Sunak’s close protection team has been arrested on suspicion of committing misconduct in public office.
It represents a further escalation in an inquiry that has derailed Mr Sunak’s election campaign.
It will also anger insiders. A source close to the Cabinet Office has already accused police of leaking the identities of the Tory suspects to the press, an allegation angrily denied by Scotland Yard.
However, a source close to the Home Office said it would be inappropriate for the police to take full control.
The source said: “It’s outrageous that an organisation reported to have been leaking the names of people involved in this investigation would be allowed to mark its own homework. Met Police officers are being investigated as part of this. How can the Met be impartial? This needs an immediate rethink.”
The first senior Tory to be implicated in the election betting scandal has been interviewed by the gambling watchdog, it has been reported.
Craig Williams, who is Rishi Sunak’s top parliamentary aide, was questioned by Gambling Commission investigators on Wednesday.
Sky News reported that he was cautioned and interviewed by a panel of three officials after a “live criminal investigation” was launched.
The interview is said to have happened just 24 hours after the Conservatives suspended Mr Williams as a parliamentary candidate.
The former Tory MP, who is contesting the Welsh seat of Montgomeryshire, has admitted taking a “flutter” on the timing of the election.
He is reported to have put £100 on a snap poll taking place in July three days before Mr Sunak publicly named the date.
The revelations came to light on June 12 when The Guardian reported that he was being investigated by the Gambling Commission.
At the time Mr Williams said: “I put a flutter on the general election some weeks ago. This has resulted in some routine inquiries and I confirm I will fully co-operate with these.
“I don’t want it to be a distraction from the campaign, I should have thought [about] how it looks.”
