Simon Cowell says One Direction's hiatus was the ''world's worst kept secret''.

The 55-year-old music mogul has admitted he's been hinting to fans for months about the break to try and avoid any heartbreak.

He told the Daily Mirror newspaper: ''I kind of hinted a few months ago they'd be having time off. We haven't had a conversation where anyone has said it is the end, but the conversations have been, 'We're exhausted, can we have time off?'

''You saw in the film we made that they went out to get shoes and within seconds they were mobbed. You can't live your life like that forever.''

Meanwhile, Simon recently admitted he would love for One Direction to do their last performance on the final of this year's 'The X Factor'.

He said: ''I would like their last performance before their break to be the 'X Factor' final, 100 per cent. I think they will come on the final of 'X Factor' this year.

''They are such a great stadium band now. They are more than just a boy band, they are a real band. The new album is incredible. I'd be amazed if anyone walks away from this for good.''