A man has been charged with punching singer Leona Lewis in the head during a book signing.

Peter Kowalczyk, 29, is accused of assaulting The X Factor star as she signed copies of her autobiography at Waterstone’s in London’s Piccadilly on Wednesday afternoon.

Kowalczyk, of south London, was also sectioned under the Mental Health Act, said Scotland Yard. He will appear at City of Westminster Magistrates’ Court on October 26.

Witnesses said the 24-year-old star had been signing autographs for about 90 minutes when the incident took place. They said a man whose book she signed lashed out, leaving Lewis with bruising to the side of her head.

Security officers stepped in and held the man on the floor until police officers arrived and arrested him. Lewis was taken to see a doctor as a precaution after being struck, but needed no further treatment.

The star cancelled a day-long promotional visit to Germany as she recovered from the ordeal.

In a statement, Lewis said: “Thank you so much for your support, it is truly overwhelming. Yesterday (Wednesday) was a horrible shock and left me extremely hurt and upset. 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.”

Rehearsals for her first major UK show are due to begin next week and it is understood Lewis is planning to press ahead with them.