The Geordie duo, both 46, divulged that none other than Gary Barlow was behind the theme song for the ITV series.
Speaking to Digital Spy, the presenters played their own quiz game, where they asked each other questions about the show.
Behind the scenes: Ant McPartlin and Declan Donnelly have revealed all the juicy secrets behind their new gameshow Limitless Win
Ant posed the question to Dec: ‘Who wrote the theme song to Ant and Dec’s Limitless Win?’
Dec immediately raised his hand, and said: ‘I know this one. It was Gary Barlow – he wrote it on his piano at home.
‘We didn’t do a crooner session with him,’ he added.
‘We should, but I don’t know what we’d do – there’s no singing in it,’ pointed out Ant.
Revelation: The Geordie duo, both 46, divulged that none other than Gary Barlow was behind the theme song for the ITV series
The pair also revealed that the show was originally called Mount Fortune before it became Limitless Win, and that a whopping 3,000 questions had been written.
Discussing some of the behind the scenes secrets, they also let slip that the gameplay of the show was run in secret facility that only a few people had access to, with even Ant and Dec not being allowed in.
It comes after the TV stars spoke to MailOnline and said they never lose sleep over whether their shows will be a success or not.
Ant said: ‘I don’t feel that much under pressure in terms of overnight figures anymore because the landscape has changed. The pressure is to get it right and to make the right show.
Put their knowledge to the test: Speaking to Digital Spy, the presenters played their own quiz game, where they asked each other questions about the show
‘It looks really good, we delivered what we set out to deliver. You’re nervous launching any new project but we’re very proud of what we’ve done. It’s the show we had in our heads.’
Dec added: ‘We’re proud. You put it out there and hope people like it. It’s a fun, exciting, dramatic watch.
‘We hope people like it as much as we do but you can never tell, can you? You feel a bit of pressure but that’s not where you have the sleepless nights, the sleepless nights are before you shoot the show.’
Explaining why they decided to do the show, Dec said: ‘We were intrigued by the idea. We loved it and got on board and helped develop it further.
Confident: Ant and Dec revealed they no longer get nervous over TV viewing figures for their shows as the ‘landscape has changed’
Meanwhile, Ant and Dec also joked their new gameshow could bankrupt ITV, as contestants compete to win an unlimited jackpot.
In what ITV say is ‘the biggest prize ever conceived’ up for grabs, the five-part series features an endless money ladder, with only a correct answer banking the cash.
If they push their luck too far, they’ll crash out of the game and lose it all.
Speaking about the limitless prize money, Ant told MailOnline: ‘We did worry that we were going to bankrupt ITV.’
‘We did have a few sleepless nights over whether the contestants would keep winning and winning and we’ve give away millions of pounds.
‘Someone could go on and win a world first when it comes to the amount of money. There is a worry that someone is going to go on forever.’
Ant & Dec were speaking to the UK’s biggest TV and movies website, Digital Spy. Ant & Dec’s Limitless Win continues tonight at 8:30pm on ITV and ITV Hub
New show: Ant and Dec also joked their new gameshow could bankrupt ITV , as contestants compete to win an unlimited jackpot