Cheryl Fernandez-Versini has blasted Simon Cowell for commenting on her weight.

The 31-year-old beauty said it was ungentlemanly for a man in his 50s to suggest she'd gained weight prior to her brief appearance on the US version of 'The X Factor' in 2011.

The former Girls Aloud star told the Daily Mirror newspaper: ''At the age of 55, he hasn't learnt that a gentleman shouldn't talk about a woman's weight.''

'The X Factor' boss caused major controversy earlier this year when he claimed Cheryl's appearance was markedly different when she turned up to film the show.

He told the Radio Times: ''We then did the first day of auditions, and she was nervous, shy, not in her comfort zone.

''She'd put on a bit of weight, but not loads. That wasn't the issue. The only way I can describe it is that it wasn't Cheryl sitting in that seat. She'd lost her confidence.''

At the time, Cheryl - who has rejoined 'The X Factor' judging panel this year - was quick to respond, telling Yahoo!: ''I heard this rumour and I think a gentleman should never speak about a woman's age or weight but that's only if you're educated on how to treat a woman.

''So, unlucky for him. And who listens to Simon Cowell these days anyway. Does anybody? I don't listen to him anymore.''