One lucky Katy Perry fan will get the chance to sing with her at the Grammy Awards as part of a new online video contest.

Devotees are being asked to upload videos of themselves singing along to Perry's I Kissed a Girl hit - and the best rendition will earn its performer the chance to shine at the Grammys.

The contest, on the Grammys official site, will make up part of this year's My Grammy Moment segment at the awards show, which will take place in Los Angeles on 8 February.

Perry is nominated in the Best Female Pop Vocal Performance category for I Kissed A Girl.