ROME - Pope Benedict XVI’s former butler on Tuesday admitted leaking confidential papal documents to an Italian journalist, saying he was venting his frustrations about Vatican officials who manipulated the Holy Father.

Paolo Gabriele, 46, told a Vatican court that he was innocent of the charges of aggravated theft, while saying that he had betrayed the Pope’s trust. Gabriele also said that he acted alone.

“I developed the conviction that it’s very easy to manipulate a person who has decision making powers in his hands,” Gabriele told the three-judge panel. “Sometimes the Pope asked questions about things he should have already known about.”

Gabriele allegedly leaked the documents to Italian journalist Gianluigi Nuzzi, who used some of them in his book “His Holiness: The Secret Papers of Benedict XVI.”

The Italian best-seller detailed power struggles and alleged corruption inside the Vatican. Gabriele, who began collecting documents more than five years ago, said frustration pushed him to confide in a journalist.

“My intention was to find a trusted person to vent to, given my feelings and the discomfort about the situation that had become unbearable all around in the Vatican,” Gabriele said.

He never accepted money or benefits in exchange for information, Gabriele said.

Vatican authorities searched Gabriele’s house and found documents as well as a check made out to the pope for $129,000, a 16th-century book and a gold nugget, according to court documents published on the Vatican’s website in August. If Gabriele is convicted, he would face a jail sentence from one to six years, Vatican spokesman Federico Lombardi said Aug. 13.

Gabriele was arrested in May after the leaks narrowed the number of potential informers. Benedict’s secretary Monsignor Georg Gaenswein, who testified Tuesday after Gabriele, said he became suspicious of the butler after the publication of three documents, including an email from Italian talk-show host Bruno Vespa.

Gabriele had a desk in Gaenswein’s office, which is adjacent to the pope’s. Gaenswein, who said that he previously trusted Gabriele “absolutely.”