Singers Rihanna and Christina Aguilera are under fire for their racy performances on the finale of British talent search 'The X Factor.' The performances took place on Dec. 11, the night before Matt Cardle was crowned the winner, but since then the British broadcasting regulator Ofcom and the show's network, ITV, have received almost 4,500 complaints, prompting an investigation into the show's finale.

Both singers, as well as their back-up dancers, wore lingerie-like outfits and provocatively shook their hips a little too much for the nearly 20 million viewers watching.

When Rihanna performed, she took off a striped tunic mid-song and showed off her curves while singing 'What's My Name?' Aguilera and her dancers, on the other hand, looked more like strippers during her performance of 'Express,' but it was similar in style to Aguilera's new movie 'Burlesque,' which features the song. Check out the videos after the jump.