VATICAN CITY — At least 20 whistle-blowers are seeking to expose corruption and incompetence at the Vatican, according to the man who is to stand trial at the Holy See this autumn accused of stealing sensitive documents and leaking them to the press, according to Britain's The Independent newspaper.

Paolo Gabriele, a 46-year-old papal butler who has three children, has been indicted for theft after investigators searching his quarters located some of the documents whose contents had found their way on to the front pages of Italian newspapers.

They included reports on the Vatican's tax affairs and one document that suggested Pope Benedict's new ambassador in Washington was exiled in the United States because he had blown the whistle on financial corruption, according to The Independent.

Despite the widespread belief that Gabriele was a pawn in a larger conspiracy, only one other person, Claudio Sciarpelletti, a 48-year-old Vatican computer expert, has been indicted so far for the "Vatileaks" scandal. He is accused of aiding and abetting Gabriele, the newspaper said.

But last night on the national La7 TV channel in an interview recorded before his arrest, Gabriele, who had his face covered, said: "The people, who like me, want to help bring some transparency number at least 20."

The Vatican has previously denied rumors that a further 20 people are under investigation in the case. The TV interview was conducted by the journalist Gianluigi Nuzzi, who has already made damaging revelations about the Holy City this year in a series of TV programmes and in his new book Sua Santita (Your Holiness).

The defense lawyer, Carlo Fusco, appeared to admit Gabriele's guilt in July when he claimed his client had only acted out of love for the Pope. Since then, Fusco has quit as Gabriele's main counsel, citing "differences on the line of defense" with other members of the team, the Independent said.

The trial date will be decided at the end of this month. A November start is considered likely to prevent proceedings from diverting attention from October celebrations to mark the 50th anniversary of the Second Vatican Council. Gabriele and Sciarpelletti are expected to be tried together.

If found guilty Gabriele could be sent to prison for up to six years. But some commentators have suggested he might be given a papal pardon. "That would play perfectly with the narrative the Vatican is trying to craft," Robert Mickens, The Tablet's Rome correspondent, said. "Instead of Pope Benedict as an evil old man, we'd see Benedict the merciful and kind."

Gabriele has said he was acting out of love for the church. But in his TV interview he also said the growing gap between Vatican hawks and reformers had created an atmosphere in which people were afraid to speak out.

In his TV interview, Gabriel said: "The Pope wants to clean up, but he is having difficulties." And adding to the intrigue, he said: "Ours is a state [Vatican City] where you can get in, kill and leave undisturbed, and after 24 hours no one can say what happened."

Vatican prosecutor Nicola Picardi has dismissed claims of a major conspiracy or conflict between power brokers behind Vatican walls. In his indictment against Gabriele he claimed the former butler was erroneously "seeing evil and corruption everywhere."

The Italian press says the damaging leaks have been designed to undermine the Vatican No 2, Cardinal Tarcisio Bertone, the Pope's right-hand man, under criticism for his handling of the foreign relations.