A controversial novel of illicit sex and corruption in the Vatican is raising temperatures inside and outside the Catholic church.

And as if the setting of Gone with the Wind in the Vatican was not bad enough, it is now suspected that the author - I Millenari - is in fact a group of priests.

Only one of them has publicly admitted his involvement: Monsignor Luigi Marinelli, a 72-year-old retired priest.

Monsignor David Lewis: "The project of someone so overcome with rancour that his mind is obscured."

Now, the Vatican has begun disciplinary proceedings against him, and he is expected to be stripped of his authority to say Mass at a disciplinary hearing in the autumn.

But he claims he is being victimised for telling the truth.

"A healthy and holy church is not afraid of the truth, even if that truth is uncomfortable," he said. "Those who have taken this action may want to teach a lesson to those of us who have been brave enough to write in this way."

The book is full of colourful but unsubstantiated tales of sex, cronyism and corruption - like the one about the bishop being blackmailed by his illegitimate daughter.

Vatican sources claim Monsignor Marinelli is angry and bitter because during his 45 years in the church, he failed to secure high office.

It is a claim he strenuously denies.

The Vatican failed in its attempt to get him to withdraw the book from sale.

Marco Tusati of La Stampa: "I don't think the Vatican is as mysterious or colourful as people think."

Indeed, the move backfired badly, with the publicity resulting in sales of 100,000 copies in the last three weeks alone.

Book-sellers say the novel, published by Kaos Edizione of Milan - is now out of print.

Foreign language editions are expected to be published in the autumn.

"It's certainly scandal-mongering," said Monsignor David Lewis, "and I think most laymen throughout the world have such good common sense that they would see immediately that this is a project of a ... not necessarily a sick mind, but a person who is so overcome with rancour and anger that he sometimes ... his mind is obscured."

But Marco Tusati, a long-time Vatican watcher for the Italian newspaper La Stampa, believes the book shouldn't be taken too seriously.

"There are scandals and maybe they are like everywhere else," he said. "But I don't think they are so mysterious and colourful and picturesque as the people think they are."