He’s only been in the jungle for four days, but John Barrowman has already broken one of the camp rules within the first 24 hours.

The on-stage and screen entertainer, 51, was asked by producers to give his vocal cords a rest while on the ITV reality show so as not to rack up a bill of royalties.

Yet within moments of filming, the Broadway and West End star could be heard putting his voice to good use, breaking into lyrics from The Sound Of Music and Home Is Where The Heart Is.

This is despite warning from bosses that his singing could become an expensive habit, with the programme having to obtain the rights to any songs played on the show.

Speaking ahead of his stint Down Under, John admitting he might belt out a few of his own tunes to scoop up some royalties.

'I discussed this with them [the producers], because I like to sing and I may burst out into song – but then they’ll have to get the rights for the song and that’s expensive,' he explained.

The boisterous celeb joked: 'Darling, the songs I sing won’t be cheap ones. I might sing a few of my own to get some residual payments in the bag!'

John has impressed audiences in hit West End musicals including Matador, Miss Saigon, The Phantom Of The Opera, and Sunset Boulevard.

The Arrow actor has also reportedly been banned from exposing his private parts while in the jungle.

An industry source told The Sun: ‘John has raised eyebrows in the past by going a bit far with his party antics.

‘He’s certainly not shy when it comes to his body, and tends to be quite impulsive and act in the moment which they hope could make him a favourite with viewers.

‘John has promised he’ll be on his best behaviour, and will be on a self-imposed flashing ban. But fully intends to show everything in the showers.’

I'm A Celebrity Get Me Out Of Here continues on Tuesday November 20 at 9pm on ITV.