Keira Knightley claims she is often mistaken for other celebrities and couldn't resist playing along when a fan thought she was Britney Spears.
The 'Begin Again' actress is often mistaken for other celebrities, including Kate Winslet and Natalie Portman, in Los Angeles and couldn't resist playing along when a fan thought she was the 'Toxic' hitmaker.
The 29-year-old star told 'The Graham Norton Show':
"It has happened to me three times in LA. I was quite excited by that and definitely signed and had a picture."
But the British beauty admitted she has very little in common with the blonde singer, 32, as she hates singing in public.
She said: "I like singing if I'm in my own in the shower or if I am really drunk, but I'm not a big fan of singing in front of people, which I didn't realise until I said yes to the movie and found myself singing in front of rather a lot of people."
She also recalled auditioning for the lead in the stage version of 'The Phantom of the Opera' in the past, saying:
"When I got to the end of the song there was absolute silence in the room and one of the producers, I think it might have been Andrew Lloyd Webber, said, 'You really can't sing.' It was the most mortifying day of my life."
Keira claimed she almost murdered her rocker husband James Righton when he tried to teach her how to play the guitar for her latest movie.
She said: "My husband tried to teach me guitar for the role, which nearly ended in divorce and murder.
"I've never been more angry - the rage is just something I have never experienced before."