La Repubblica said the leaking of the documents showed that Paolo Gabriele, who is currently held in the Vatican, "is not the only one" responsible for the so-called Vatileaks scandal which has engulfed the Vatican.
La Repubblica published part of what it said was an anonymous, computer-typed message carrying the heading: "Chase away from the Vatican, those really responsible (for the scandal)."
The message claims that the Vatican's second highest official, Secretary of State Cardinal Tarcisio Bertone, and Pope Benedict XVI's personal secretary Monsignor Georg Gaenswein, are the main culprits in an unspecified plot.
The message to La Repubblica was accompanied by copies of three documents, including a letter dated January 14 and addressed to Bertone.
It was purportedly written by Cardinal Raymond Burke, who heads of the Catholic Church's highest judicial authority, the Supreme Tribunal of the Aspostolic Signatura.
In the letter, Burke criticises a Catholic group, the Neocatechumenal Way, for staging ceremonies thar are at odds with Church liturgical teachings, and also raises concerns that the pope may soon give his approval to such ceremonies.
The other two leaked documents received by La Repubblica bore Gaenswein's signature, but with the rest of the contents deleted, possibly with corrective fluid, the newspaper said.
The Vatican has said that a magistrate would next week begin to formally question Gabriele who was arrested on May 25 after confidential documents, including papal letters, were discovered in the flat he shares with his wife and three children.