Former X Factor winner Leona Lewis has been slapped at a book signing in London, it's been reported.

The incident is said to have taken place at Waterstones book store in Piccadilly as she signed copies of her autobiography, Dreams.

According to the BBC, police were called to the store, which is still open.

A spokesman for Scotland Yard told Sky News: "We were called to Waterstones Piccadilly Circus at 4:35pm to reports of an assault.

"It appears that a male has slapped a female at the location."

Dreams, the 24-year-old's first book, includes dialogue about the singer's life, as well as 100 new photographs taken by Dean Freeman.

Lewis's debut album 'Spirit' has sold nearly five million copies around the world since it was released in 2007.

(by Jason Gregory)