Sales of Fifty Shades of Grey take a tumble

Author E L James is looking to adapt her best-selling erotic novel, Fifty Shades of Grey, for the big screen (AP)

Sales of E L James’ enormously successful erotic novel Fifty Shades of Grey have fallen sharply after increasing for eight consecutive weeks.

Sales slipped by 16 per cent last week to 1.21m (£5.4m) according to trade magazine The Bookseller.