Cheryl Fernandez-Versini is unconvinced by the authenticity of Kim Kardashian's nude shoot for Paper Magazine.
The controversial images show Kim's body covered in oil as she exposes her famous rear - but Cheryl, 31, isn't convinced that the images haven't been tampered with.
She said: "I don't think it's real.
"I'll refrain from judgement because each to their own. But I would never do it. I could never. I could never. I could never."
Despite attracting attention for posting a picture of her own tattooed backside online last year, Cheryl insists she's uncomfortable about stripping off in front of people she barely knows.
The 'X Factor' judge told The Sun newspaper: "I can't even get changed in front of my stylist who I've had for years. Just no."
Cheryl sent a message of support to Kim, 34, last year after she was attacked over her pregnancy body and taste in fashion.
Back then, Cheryl tweeted: "Just wanted to send you a tweet to say I think you are an incredibly beautiful woman inside and out.
"I can only imagine how tough it is to be heavily pregnant and feeling extremely vulnerable on top of some of the daily criticism you take! I admire your tenacity and send you my best wishes with the rest of your pregnancy #enjoyyourblessing x (sic)"