Williams, 36, said he never made the comment but it was his management that told her she wasn't to go any further than a professional relationship with him.
Speaking to Glamour magazine about a photo from 1998, he said: 'That's Gina, my long-suffering make-up artist. She got the job because she refused to sleep with me. I didn't ask her, but the management were like: 'You can't sleep with him - promise.'
'I've got a canny management who could see a possible pattern emerging. [She said] 'Yeah, promise.' And she's worked with me ever since.'