A stash of explicit pornography to which Franz Kafka subscribed has emerged for the first time after being studiously ignored by scholars anxious to preserve the iconic writer's saintly image.

Even today, the pornography would be "on the top shelf", Dr Hawes said, noting that his American publisher did not want him to publish it at first. "These are not naughty postcards from the beach. They are undoubtedly porn, pure and simple. Some of it is quite dark, with animals committing fellatio and girl-on-girl action... It's quite unpleasant."

"Academics have pretended it did not exist," Dr Hawes said. “The Kafka industry doesn’t want to know such things about its idol."