The X Factor has escaped punishment from Ofcom for airing racy routines from Christina Aguilera and Rihanna during last year's final.

The broadcasting watchdog said it received 2,868 complaints about the "sexually explicit" performances. Many who wrote in said the scenes were not suitable for family audiences.

But Ofcom ruled that despite "some gentle thrusting" from Rihanna, her bikini-clad performance was not inappropriate for the time of its broadcast.

And though Aguilera's burlesque routine "was at the very margin of acceptability" it was "editorially justified" because it reflected the theme and storyline of the singer's film Burlesque.

Ofcom said: "...The performance by Rihanna was presented in a style which would not have exceeded the likely expectations of the audience."

It did however say that Aguilera's performance, which featured dancers "repeatedly shaking and playfully slapping their buttocks", should not have been repeated at times when children were likely to see it.

"The cumulative effect of the repeated close up images of the female dancers' buttocks, together with some of the provocative dancing and actions in the video, resulted in the video's imagery conveying a highly sexualised theme," Ofcom said.