The N-Dubz star has apparently been smoking backstage and allowing friends to hang out with her until the early hours.

© Ken McKay/Thames/Rex Features

© Ken McKay/Thames/Rex Features
Studio staff can't close the building until the parties have finished because she refuses to leave, The Sun claims.
"It's just not very professional. She's smoking in her dressing room in the breaks and it's full of her chavvy pals all drinking from her minibar," a source said.
"When they won't leave it means the security staff are stuck there waiting to lock up."
Producers apparently want the judges to set better examples for their acts after Rylan Clark and Lucy Spraggan were kicked out of London's Corinthia Hotel. It is feared all the contestants could be asked to leave over their increasingly wild behaviour.
Photo gallery - X Factor controversies:

Sharon Osbourne throws a glass of water over Louis Walsh after he threatened to quit the ITV show over alleged "bullying" by fellow judges including Osbourne and Simon Cowell back in series 2.
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Copyright: Rex Features Ken McKay/Rex Features
The source continued: "How can we expect the contestants to behave when the judges aren't?"X Factor bosses recently stated that they had been "too cautious" after asking Dermot O'Leary to apologise to viewers over Contostavlos's use of the word 'MILF' on Saturday's (October 13) live show.
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