HARRY POTTER star Emma Watson had an odd encounter with a superfan on the New York subway - after she managed to convince him she wasn't who he thought she was.

The actress admits she can get away with riding on public transport in the Big Apple because people refuse to believe Watson would use buses and trains to get around the city.

And it's very easy to convince fans she's just a look-alike, who gets mistaken for Watson all the time.

She tells Nylon magazine, "He (fan) went, 'Oh my God, are you...' and I was like, 'Oh my God, he's about to recognise me and this entire car of people are going to stare at me'... I was going into panic mode, and then he said, 'It's obviously not you, why would you be riding the subway?'

"But then things got really terrifying, and he proceeded to tell me everything about myself, not realising it was me. He was like, 'You know what's weird, she's supposed to be in New York, like, right now...' and he started talking to me about what he thought about my choice of university and all this stuff, and I just had to sit there and listen for 20 minutes.

"That kind of experience just gives me chills because I realise who I am as a person and the way people construct this idea of who Emma Watson is are such different things - they're so far removed."