Harry Potter star parties with Borrell

Harry Potter star Emma Watson has been spotted partying with Razorlight's Johnny Borrell in London.

The pair attended a Vanity Fair party at the National Portrait Gallery and reportedly left together in a taxi.

According to the Daily Star, Borrell, 27, didn't realise who Watson was until they left the bash and fans started calling her name.

"They were very taken by each other," said a source.

He has previously dated Spider-Man star Kirsten Dunst, but they split after he claimed the actress couldn't put up with his rock 'n' roll lifestyle.

Watson, 17, was romantically linked with rugby player Tom Ducker last summer.

An insider told The Sun: "She seemed really happy. She’s a Razorlight fan and was star-struck."