Alister Jack, the Scotland Secretary, made three bets about the July 4 poll’s timetable, although he said he had not broken any gambling laws.
The Gambling Commission is looking into five Metropolitan Police officers in addition to seven lawmakers; one policeman has already been detained and interrogated.
Labour became embroiled in the controversy on Tuesday, suspending candidate Kevin Craig after word that the Gambling Commission had opened an inquiry into him.
In the Suffolk seat he is running for, Mr. Craig that he “deeply” regrets betting for the Tories and that he would “fully comply” with a Gambling Commission probe.
In response to oppositional and party criticism, Rishi Sunak banned two candidates on Tuesday. Since nominations have closed, Craig Williams, who is running in Montgomeryshire and Glyndwr, and Laura Saunders, who is running in Bristol North West, will continue to be included on ballots during the election.