Vatican magistrates formally charged Pope Benedict's butler with illegal possession of secret documents on Saturday and said a wider investigation would take place to see if he had any accomplices who helped him leak them.

Paolo Gabriele is suspected of leaking highly sensitive documents, some alleging cronyism and corruption in Vatican contracts, in a scandal which has come to be known as "Vatileaks".

A statement referred to Gabriele, 46, who was until his arrest on Wednesday night serving the Pope meals and helping him dress, as "the defendant".

It said a preliminary investigation had been upgraded to a "formal investigation," meaning he had been formally charged, and had chosen two lawyers to defend him.

Because the Vatican has no jail, Gabriele was being held in one of the three so-called "secure rooms" in the offices of the Vatican's tiny police force inside the walled city-state.

The Vatican promised that he would have "all the juridical guarantees foreseen by the criminal code of the State of Vatican City."

The Vatican said the upgraded, formal investigation "would continue "until a sufficient framework of the situation is acquired," which a Vatican official said meant magistrates wanted to determine if Gabriele acted alone or with others.

The Pope was said to be "pained" that someone in his domestic household had betrayed him. Gabriele lived in the Vatican with his wife and three children.

Commentators in Italian newspapers said they doubted that Gabriele could have acted alone and some speculated that he may have been a pawn in a larger, internal power struggle.

"Never has the sense of disorientation in the Catholic Church reached these levels," Church historian Alberto Melloni wrote in Italy's Corriere della Sera newspaper.

"But now there is something even more - a sense of systemic disorder."

Web of corruption and cronyism

If convicted, Gabriele could face a sentence of up to 30 years for illegal possession of documents of a head of state. He would likely serve any time in an Italian jail because of an agreement between Italy and the Vatican.

The scandal involves the leaking of a string of documents to Italian media in January and February, including personal letters to the Pope.

Some of the documents involved allegations of corruption, mismanagement and cronyism in the awarding of contracts for work in the Vatican and internal disagreement on the management of the Vatican bank.

Gabriele worked in the papal apartments of the Apostolic Palace, serving at the papal tables, handing rosaries to visiting dignitaries and riding in the first seat of the Popemobile at papal audiences.

He was privy to the goings on in the most reserved and private rooms in the Vatican.

The Pope had ordered several investigations into the leaks, including one headed by Vatican police and another by a commission of cardinals.

The leaked documents included letters by an archbishop who was transferred to Washington after he blew the whistle on what he saw as a web of corruption and cronyism, a memo which put a number of cardinals in a bad light, and documents alleging internal conflicts about the Vatican Bank.

In January, an Italian television investigation broadcast private letters to secretary of state Cardinal Tarcisio Bertone and the pope from Archbishop Carlo Maria Vigano, the former deputy governor of Vatican City and currently the Holy See's ambassador in Washington.

The letters showed that Archbishop Vigano was transferred after he exposed what he argued was a web of corruption, nepotism and cronyism linked to the awarding of contracts to Italian contractors at inflated prices.

In one letter, Archbishop Vigano wrote of a smear campaign against him by other Vatican officials who were upset that he had taken drastic steps to clean up the purchasing procedures. He begged to stay in the job to finish what he had started.

Cardinal Bertone responded by removing Archbishop Vigano from his position three years before the end of his tenure and sending him to the United States, despite his strong resistance.

Reuters