Lewis posed for photographs before Wednesday's book signing
A man has been charged with assaulting pop star Leona Lewis at a book signing and sectioned under the Mental Health Act, Scotland Yard has said.
Peter Kopwalczyk, 29, of south London, is accused of common assault after Lewis was punched in the head at a book store in central London on Wednesday.
He will appear at City of Westminster Magistrates' Court on October 26.
Earlier in a statement, Lewis, who won ITV1's X Factor in 2006, said she had been left "extremely hurt and upset".
Lewis, 24, had been signing copies of her forthcoming autobiography, Dreams, at the event, but cut her visit short after she was hit.
She told fans: "I'm very sorry to those I wasn't able to meet at the signing.
"Thank you again for all of the lovely messages. Love you all."
She also cancelled a day-long promotional visit to Germany on Thursday as she recovered.
The three-time Grammy Award nominee released her debut single A Moment Like This shortly after winning X Factor three years ago and has enjoyed chart success on both sides of the Atlantic.
Lewis's second album, Echo, is scheduled for release in November.