X Factor judge Simon Cowell admitted he is ‘appalled’ by the way he has treated contestants on TV talent shows.

The hard-to-please media mogul said he looks back at some shows and realises he has ‘gone too far’ when he sees how brutal he has been.

The 50-year-old said on Piers Morgan’s Life Stories, to be broadcast on ITV1 on Saturday: “There’s many, many times where I’ve watched the show back and I’m absolutely appalled – you do the show, you’re not aware of what’s happening in the room outside.”

He went on: “You know, somebody just said ‘My dog Lassie died yesterday’, I’m in a bad mood and, you know, awful, and you see it in that context, it’s very, very difficult to watch.”

Simon said it was easy to get caught up with the mood of the audience. “You become part of a mob and when you watch the show back you realise that you’ve gone too far,” he said.

Simon also revealed about how he initially failed to provide enough support for Susan Boyle when she began to struggle with the pressure of fame.

He told Piers he did not appreciate the impact that TV would have on the Britain’s Got Talent winner.

He said: “I don’t think that for one second when I saw that (audition) tape that any of us suddenly went, ‘What are the repercussions for her?’

“That’s when you suddenly realise, ‘I haven’t thought about this person as a human being.’ And it was a real wake-up call I’ve got to tell you.”