The Crown Prosecution Service has dropped a rare case brought under the Obscene Publications Act against a man who wrote a violent pornographic story about the pop group Girls Aloud.

The report appeared on a website and one of the reasons the CPS dropped the case was that it was difficult to find online.

Jo Glanville, editor of Index on Censorship, said: “Since the landmark obscenity cases of the 60s and 70s, writers have been protected from such prosecutions and have remained free to explore the extremes of human behaviour. This case posed a serious threat to that freedom.”