However, late on Thursday night time he admitted inserting a £20 wager on a July election in April.
The senior Scottish Tory mentioned he had not damaged any guidelines and was not underneath investigation by the Gambling Commission.
The extraordinary revelation got here simply hours after the Conservative Party withdrew assist from two candidates who additionally gambled on the timing of the vote.
READ MORE: Tories withdraw support for candidates accused of election bets
“I am very clear that I have never, on any occasion, broken any Gambling Commission rules”, Mr Jack advised the broadcaster.
“I didn’t place any bets on the date of the final election throughout May – the interval underneath investigation by the Gambling Commission.
“Furthermore, I am not aware of any family or friends placing bets. I have nothing more to say on this matter.”
Later on Tuesday, he mentioned: “Following studies at the moment I wish to be completely clear I’ve not breached any playing guidelines.
“I positioned two unsuccessful bets on the date of the final election and one profitable one.
“I put two bets on in March of £5 every for an election to be held in May and June respectively.
“In April, I put £20 at 5 to 1 on an election being held between July and September.
“I had no data of the date of the election till the day it was known as.
“As I have said previously, I placed no bets in May and am not under investigation by the Gambling Commission.”
The BBC says Mr Jack had been telling colleagues and journalists for at the least a 12 months that he thought a June or July election made essentially the most strategic sense for his celebration.
Last week, when requested in regards to the feedback, Mr Jack advised the BBC they have been “a joke… I was pulling your leg”.
Mr Jack just isn’t standing on the election, and had been extensively anticipated to take up a seat within the House of Lords.
A spokesperson for the Gambling Commission mentioned: “We are not confirming or denying the identity of any individuals involved in this investigation.”
Earlier within the day, the Tories withdrew assist Craig Williams, the candidate in Montgomeryshire and Glyndŵr, and Laura Saunders, the candidate in Bristol North West.
Both are being appeared into by the Gambling Commission.
As the deadline for nominations has closed, they are going to nonetheless be on the poll paper as Conservatives.
Mr Williams, an aide to Mr Sunak, has already admitted inserting the wager two days earlier than Mr Sunak known as the election.
As effectively because the candidates, two senior Tory officers underneath investigation have additionally taken a go away of absence, together with Ms Saunders’ husband, Tony Lee, the celebration’s marketing campaign director.
A Tory Party spokesman mentioned: “As a consequence of ongoing inner inquiries, we’ve got concluded that we are able to now not assist Craig Williams or Laura Saunders as parliamentary candidates on the forthcoming General Election.
“We have checked with the Gambling Commission that this decision does not compromise the investigation that they are conducting, which is rightly independent and ongoing.”
Liberal Democrat deputy chief Daisy Cooper wrote on X: “This ought to have occurred instantly when these scandalous revelations emerged, however as a substitute Rishi Sunak has dithered and delayed.”
READ MORE: Labour withdraw support for candidate over betting against himself
The Met Police has additionally confirmed that 5 additional officers are being appeared into by the Gambling Commission.
One of the Prime Minister’s shut safety officers has already been arrested.
Meanwhile, in a separate growth, Labour has suspended a candidate who wager in opposition to himself.
Kevin Craig admitted making a “stupid error of judgment” after placing cash on the Tories defeating him within the constituency of Central Suffolk and North Ipswich.
He claimed he had completed so as a result of he thought he would “never win this seat” and had been planning to present any winnings to native charities.
A Labour spokeswoman mentioned: “With Keir Starmer as leader, the Labour party upholds the highest standards for our parliamentary candidates, as the public rightly expects from any party hoping to serve, which is why we have acted immediately in this case.”
According to studies, the celebration has additionally since handed again £100,000 in donations it obtained from Mr Craig.