Paolo Gabriele was arrested May 23, so far the only person ensnared in a criminal investigation.
He was released under house arrest July 21 pending a decision on whether to indict him.
Gabriele's lawyers have told reporters that Gabriele had fully cooperated with the investigation, and that they would be ready to face a trial in case of an indictment, which they say they expect.
They deny that he was part of any conspiracy.
The documents point to corruption and power struggles in the church hierarchy.