One Direction are "raging" over their reported sex ban, says a source.

The boy band - comprising of Harry Styles, Niall Horan, Zayn Malik, Liam Payne and Louis Tomlinson recently made music history by becoming the first British group to top the US charts with their debut album. The group already have a loyal female fan base, however their record label bosses are reportedly keen to protect their clean-cut image over in the States.

Executives are said to have put a sex ban on the stars in order to keep their focus on music. The boys are allegedly unhappy with the imposed rule.

"He's raging about it all the lads are," a source close to Niall told British newspaper The Sun. "Four of them are single and they've been told to stay that way as it appeals to their American teen fans. Niall is fighting off the women with his Irish accent and good looks so he's having to live like a monk.

"Niall and the boys are being kept on a really tight leash and it is tough for them. But they are so determined to make it work in the States they'll do whatever they are told. Quite simply a sex scandal over there would be the end of the band."

Bandmate Harry only recently became single. The star is reportedly dejected with the band's new rule.

"He's come out of a relationship and wants to enjoy his freedom. But he's having to behave himself and keep the women at arm's length," the source continued. "They are all young lads and they have urges like anyone else their age.

"And the worst thing is the American girls are literally throwing themselves at them so there is so much temptation in their way."