The butler, Paolo Gabriele, admitted to leaking the papers to Italian journalist Gianluigi Nuzzi, who then used the information in his best-selling book "His Holiness," CNN reported.
Vatican IT expert Claudio Sciarpelletti will be charged with aiding Gabriele, a Vatican spokesman, the Rev. Federico Lombardi, said.
The Vatican has called the publication of Nuzzi's book criminal because it is a breach of privacy, not because the information is inauthentic, CNN reported.
The book depicts an internal power struggle within the Vatican hierarchy through documents, including faxes, personal letters and Vatican memos found in the pope's personal apartment, CNN reported.
Nuzzi refused to identify his source within the Vatican, referring to the person only as "Maria" in the book. He said his primary source "risked life and limb" if ever discovered.