In a telephone interview, Mr Kafka was contrite and tearful. “I know what I did was wrong,” he said. “I’m very alienated from myself, but that’s no excuse to lie. I took someone’s life and selfishly turned it into an enigmatic literary parable.”

“I’m not sure how this happened,” said Mr Kafka’s brother, B., of Oxnard, Calif. “My brother is weird, but he doesn’t have that good an imagination. A man who becomes a big bug... my brother couldn’t make that up if his life depended on it. As soon as I read The Metamorphosis I knew it was true. Don’t they fact-check fiction?”

Mr Kafka’s publishers are now reviewing all his works of fiction — stories about singing mice, “hunger artists” and men on trial for crimes they’re not aware of having committed — to determine whether they too are true.

“We were duped,” said E., Mr Kafka’s editor. “The whole story is pure, unadulterated non-fiction. This guy’s a complete con man.”

Mark Leyner is a novelist and screenwriter