British singer Robbie Williams has denied he is to be one of the judges on this year's (15) U.K. version of The X Factor.

Rumors about the four-strong judging panel have swirled since Irish pop mogul Louis Walsh announced he was leaving the talent show earlier this year.

However Williams, who is known to be a huge fan of The X Factor and even appeared on it as a mentor, has denied he is to be a judge on the next series of the show.

He tweeted, "Said it once, I'll say it again: I'm unequivocally not doing X-Factor. Good luck to the show though."

Head judge Simon Cowell has remained tight-lipped over the identities of this year's new judges, despite reports that Radio 1 DJ Nick Grimshaw has a seat on the panel, according to Louis Walsh.