Prank: Emma is determined to find out who was behind the fake pictures
The 20-year-old actress – Hermione in the film series – is said to be appalled that the snap, apparently of her with a towel around her waist standing by a hot tub, has been emailed between students at the prestigious Brown University.
‘Emma is trying to seek out the source so she can put a stop to it,’ says a friend. ‘She says the picture has been faked.’
Emma’s spokesman said: ‘There have been a number of nude fakes over the past two months. Emma has seen them and finds them tiresome. People should know better.’
Meanwhile Watson revealed she is all grown up - by declaring: 'It's time I got more naughty.'
In an interview following the filming of her final scenes, she revealed how she will be making the most of being a single girl.
She told The Sun: 'I wished I'd done more naughty things.Three months ago I cut my hair and at that moment I felt I became a woman. I'm ready to start taking risks.
'I've been in love once in my life, but it was complicated. I can't tell you who it was because it wouldn't be fair to any others. But I can say I've never had my heart broken.
Prestigious: Brown's University campus on Rhode Island where Emma Watson is the centre of attention
Final scenes: Emma with Harry Potter co-stars in the final film