Officials at the U.K.'s broadcasting standards watchdog have launched a probe into Simon Cowell's talent show The X Factor after more than a thousand outraged viewers complained about raunchy performances by Rihanna and Christina Aguilera.
The two pop princesses appeared on the final of the singing contest on Saturday (11Dec10), duetting with contestants as they battled it out for the title.
Later, both stars sang a song of their own - but their performances have sparked fury amid claims they were too explicit for a primetime audience.
Umbrella hitmaker Rihanna raised eyebrows when she took to the stage dressed in a bra and knickers, and Aguilera turned the heat up even more with a raunchy routine from her new movie, Burlesque.
More than 1,000 viewers complained about the performances to officials at the Office of Communications (Ofcom), and an investigation has now been launched.