Knightley horrified by writer mum's 'filth'

Actress Keira Knightley was stunned when she first discovered her writer mother's penchant for penning naughty fiction - after finding a saucy book in her school library.

Knightley's mother, Sharman MacDonaled, was one of the writers at the forefront of the sexual revolution and her books were popular among lusty teens - something her daughter discovered at school.