Bearded and bespectacled Dieter Henning, a 47-year-old father of four who teaches at the Ernestinum High School in the southern German town of Coburg, seems an unlikely scandaliser of society.

Indeed, when he published his first novel Pueppchen, Pueppchen (Dolly, Dolly) in autumn 1993, it was scarcely noticed, selling only 900 copies out of a print run of 4,000. But when, a year after publication, a copy found its way to the Bavarian education ministry, the author became an overnight celebrity. A ministry official wrote to Herr Henning’s headmaster claiming the book contained “massive obscenities and even blasphemy”, with unappetising accounts of sexual and scatological details that were beyond the bounds of good taste.

The letter, widely quoted in the German media, said that the book called into question the author’s suitability as a teacher. Female pupils in particular might find it upsetting “to be taught by a teacher whose fantasies of obscenity need to be so saturated”, the letter said.

When the ministry went public with its concerns, interest suddenly soared in Herr Henning’s book, the story of an unfulfilled customs officer who decides to celebrate his 44th birthday with four blow-up dolls.

Fellow colleagues organised readings, and Herr Henning’s pupils wrote to their local newspaper assuring the bureaucrats that they were not in the least bit scandalised. “We have read hotter stuff than that,” they said.

Herr Henning was invited on to television talk shows including one in which the presenter rang the official responsible for the letter from the studio to ask for an explanation (none was forth-coming).

The author admits his publishers are overjoyed about all the publicity, although he has mixed feelings: “Of course it is nice to have one’s book noticed, but not to be known as a pornographer.” He said the book is intended as a critique of modern attitudes to sexuality.

Herr Henning believes a strong streak of Bavarian Catholic conservatism lies behind the complaint against him. His future in teaching is still on the line, but he believes the publicity will protect his job.

Gert Heidenreich, president of the PEN Centre, an association for writers, said: “I know of no other case in which someone’s literary work has had to be compatible with their duty as a civil service employee. Obviously teachers, many of whom are also writers, are supposed to be scared off by this.”

Herr Henning, however, is already working on his second novel, due to appear next autumn. The subject? A teacher who falls in love with a pupil ..