American Idol judge Simon Cowell found the prospect of fame as a TV personality terrifying, as he feared his raunchy past would be dragged up by former girlfriends.

The pop guru was initially wary of judging his breakthrough British show Pop Idol in 2001, but UK publicist guru Max Clifford persuaded him not to worry so much about his public image.

Cowell says, "I'd seen what can happen to people, particularly if, like me, you've led a rather raunchy life that could spark off kiss-and-tell stories.

"The kiss-and-tell stories were coming from every direction and I didn't like it.

"I phoned Max. But instead of sympathising, he told me to think about what I'd achieved and not take myself too seriously.

"In fact, he'd managed to keep several stories by vindictive former girlfriends out of the papers and tipped me off about others trying to set me up."

And Clifford credits himself with encouraging Cowell's nasty persona, as it made for compelling television.

He explains, "Although 95 per cent of the comments were Simon's, I did at first give him the odd line.

"But as the weeks went by, he didn't even need the odd line."