Madonna and Robbie Williams are being lined up to appear on the next series of The X Factor, it's been reported.

Rihanna and Whitney Houston have also apparently been coaxed by Simon Cowell to act as mentor's to the show's finalists.

The official line up has yet to be revealed, but X Factor choreographer Brian Friendman is said to have divulged the names during filming.

"Brian is really excited about this year's show because there are some great artists involved,” a source told The Sun newspaper.

“He is proud to be part of it and admires Simon's ability to attract A-listers."

Previous series have featured guest appearances from the likes of Westlife and Beyonce.

Meanwhile, Kate Moss is also reported to be making an appearance on the new series, which begins later this month.

Madonna