Paolo Gabriele was sentenced to 18 months in prison in 2012 for stealing documents which revealed fraud scandals and intrigue at the heart of the Catholic church.
He died aged 54 “after a long illness”, leaving his wife and three children, according to Vatican News, the Holy See’s news outlet.
Gabriele was pardoned by Benedict after serving less than three months in jail for the so-called “Vatileaks” scandal.
But he was banished from the tiny city state where he had been one of only around 600 citizens.
Gabriele had had unique access to the pontiff for a layman, helping him don his robes and accompanying him on his many foreign trips.
He said he acted out of love for the church and the pope, railing against what he called “evil and corruption” at the Vatican.