AceShowbiz -

Though Justin Bieber has thousands of devotees around the world and becomes one of the pop sensations, "Harry Potter" star Daniel Radcliffe admitted he knew little about him. Not that Radcliffe didn't know Bieber is a singer but he at first thought Bieber was a woman.

During a recent interview with MTV News, Radcliffe said, "I only heard Justin Bieber for the first time two weeks ago. I genuinely thought it was a woman singing." He continued, "I'd never heard it before. Is it big in England yet? I'm so out of the loop when it comes to pop culture that I kind of don't even try anymore." Meanwhile, Bieber has not yet responded on his comment.

Radcliffe, however, knew about another sensational singer, Lady GaGa, calling her "amazing". The 20-year-old British actor shared, "She's really got a voice. My god. Not my kind of music particularly but she can really sing."

Daniel Radcliffe will have a busy schedule ahead of him. Beside reprising his role as young wizard Harry Potter in "Harry Potter and the Deathly Hallows: Part I" and "Harry Potter and the Deathly Hallows: Part II", he also has to prepare his Broadway return on "How to Succeed in Business Without Really Trying" which will be run in the spring of 2011.