The inquiry into bets on the date of the general election has been widened with bookmakers being asked to provide details on all bets over £20.
The Gambling Commission is believed to have written to leading bookmakers to get information on bets placed days before Rishi Sunak announced the election would take place on 4 July.
The watchdog’s early investigation has also reportedly brought to light “many more people”, and it is now looking at bets made in the days before Mr Sunak gave the date of the election on 22 May.
Former cabinet ministers have pointed the blame at Mr Sunak for the scandal, while others have called for those investigated to be suspended if found guilty.
On Saturday night, The Sunday Times reported that Tory data chief Nick Mason was being investigated, becoming the fourth Conservative to be probed on the issue. Mr Mason denies any wrongdoing.
Home Secretary James Cleverly said he had no knowledge of ministers placing bets on the timing of the election.
“My view has always been the case that people in government should focus on delivering for the people of this country.”
