Pope Benedict XVI’s former butler Paolo Gabriele is set to take the stand for the first time Tuesday, the second day of his trial, for stealing the confidential documents which he said was an attempt to expose corruption in the Vatican.

Gabriele, accused of leaking hundreds of documents of fraud and conspiracy among senior Vatican officials to an Italian journalist, was arrested in May and has served 53 days in detention in a Vatican security cell, reported AFP.

The 46-year-old butler has admitted to have photocopied and passed on secret memos which were published in May by investigative journalist Gianluigi Nuzzi in the book "His Holiness: The Secret Papers of Benedict XVI.”

Among the published documents was a letter to the Pope from the head of Holy See’s governorate, Monsignor Carlo Maria Vigano, who complained of resistance from clergymen to his efforts to crack down on corruption in contracts for the public works at the Vatican.

The documents also revealed that some of the donors who sent millions to the Vatican had asked for favors in return to merit their businesses.

The papers showed clergymen accusing each other of wrongdoing, and revealed the rising concerns in the Vatican over the global financial crisis, tax pressure from governments and increasing legal costs in connection with pedophilia scandals.

The butler was arrested in connection with the case, dubbed "Vatileaks,” after investigators seized 82 boxes of evidence from the apartment where he lived with his wife and three children, Reuters reported.

Gabriele suffered a setback on the first day of the trial Saturday when the court refused to accept as evidence an inquiry by a commission of cardinals who questioned the Vatican staff about the leak, news reports said. The commission found that Gabriele resorted to leaking the memos because he saw "evil and corruption everywhere in the Church,” without adequate action from the Pope.

Chief Judge Giuseppe Dalla Torre discredited the commission’s evidence saying the evidence gathered by a prosecutor and the Vatican police alone would be allowed in the trial. The court is expected to reach a verdict by the end of the week, BBC has reported.