The father of One Direction star Niall Horan has admitted that he is worried about what will happen to his son if the band lose popularity.

Speaking to radio station 2FM, Bobby Horan spoke about his fears for Niall and the boys should One Direction lose their momentum in the future.

He intimated that there would be a "big drop" should that be the case. He said:

"The only thing I'm worried about is hopefully it'll be a long period being at the top. The comedown from that, I'm a little bit worried about. It's always at the back of my mind. You're up there on a high, but it's a big drop after that."

He added: "But he seems to be coping with everything brilliantly - a lot better than I would."

Talking about One Direction's immediate rise to No.1 in the US album chart, Horan said that his son wasn't expecting to actually hit the top spot. He said:

"Niall told me on Tuesday night that they were going to get to number one. It was a surprise to him, and it was to us as well. We thought they were going to be close but they didn't think they'd make number one. Thank God they did."