London, Nov 20 (IANS): Singer Cheryl's performance on "X Factor" has sparked complaints to watchdog Ofcom from viewers, who deemed her set "too raunchy".

The 35-year-old singer made a return to the ITV show where she once served as a judge to perform her comeback single "Love Made Me Do It", but a number of viewers were upset by her racy stage antics during her pre-watershed appearance.

She was seen gyrating against musclebound male dancers, gyrating and writhing around on the floor and suggestively licking her hand as she put on a performance which divided viewers, a number of whom slammed her "terrible vocals", reports dailymail.co.uk.

The mother-of-one's live unveiling of her single attracted 15 complaints to Ofcom from viewers, who were far from impressed with her stage antics, which were aired before the 9 p.m. watershed.

An Ofcom spokesperson told MailOnline: "We are assessing these complaints against our broadcasting rules before deciding whether or not to investigate."

Cheryl began her routine by crawling along the floor, delivering a sultry dance routine - but some viewers weren't convinced by her live vocals, with some branding her "terrible", saying she should "give up".

And even head judge Simon Cowell was seen questioning whether she was OK as she lay on her back at the end of her performance, in a puff of smoke.

The singer looked incredible in a tasselled black bodysuit and thigh-high boots for her big return and other viewers defended her saying 'she can't win' and praising her 'amazing' stage show.