The Gambling Commission, which has no power to arrest suspects, acknowledges that it works closely with police forces after it has gathered evidence.

It also declined to say whether the names that have appeared in the public domain had already been passed to the Me for help with its inquiries.

A spokesman for the Gambling Commission said: “We cannot comment in this case when information was passed over to the police.”

In a statement, a Scotland Yard spokesman said: “The Met is not currently carrying out any other criminal investigations relating to alleged betting offences linked to the election. We continue to liaise with the Gambling Commission and are assessing information that they have provided.”

On Monday, Mr Sunak, who has ordered an internal inquiry to run separately to the Gambling Commission investigation, said he was “incredibly angry when I learned about the allegations, as everybody would be when they would hear about something like that”.

He said he was not aware of any other Tory candidates being investigated but stressed that any internal inquiries by the Conservative Party must not “compromise the integrity of a police and other investigations”.

‘Self-inflicted distraction’

He also appeared to clear the commission of leaking suspects’ names, adding: “[The Gambling Commission] don’t talk about the individuals that they are investigating… What I can tell you is I am not aware of any other candidate that they are looking at.”

Mr Sunak has resisted withdrawing the whip from election candidates allegedly involved in placing bets, including Mr Williams and Laura Saunders, the Tory candidate for Bristol North West, who is married to Mr Lee.

On Monday, Tobias Ellwood, the Conservative candidate for Bournemouth East and a former minister, said the scandal was a “deeply unhelpful, self-inflicted distraction” and suggested Mr Sunak should have suspended those being investigated.

Sir Keir Starmer, the the Labour leader, said Mr Sunak’s parallel investigation showed a “total failure of leadership”, adding: “He’s announced an investigation, an investigation designed for one purpose, which is to knock this in the long grass to the other side of the election.

“The desperation over this betting story that’s going around – it goes to the heart of what the Tories have become when their first instinct in relation to a general election is not how to serve the country, how do I get the message out, it’s how quickly can I get to the bookies and make some money.”

Nigel Farage, the Reform UK leader, weighed into the row, accusing the Conservatives of seeming to “resemble something of an organised betting ring”. Mr Farage predicted that the allegations “will get worse”.