Simon Cowell has admitted that he never predicted One Direction would become so big.

The British boyband were pieced together from solo contestants on the 2010 series of the X Factor and they have gone on to achieve worldwide success.

Cowell oversaw their development on the X Factor but he told MTV News that he never realised the young quintet would become quite so massive. When asked if he thought One Direction would become as big as they are, the X Factor supremo said:

"No! I mean, you know, I thought they would work as a band, but you can't predict these kinds of things."

Cowell continued: "But it's down to them. They've worked hard. They work really well as a group. The records are good. They're nice guys to work with. So the world, right now, is theirs."