VATICAN CITY Paolo Gabriele was always a reserved, almost shy man, as his position required. He had access to the most private rooms in the Vatican's Apostolic Palace - Pope Benedict's apartment.
But what could have prompted the pope's butler, who was formally charged by Vatican magistrates on Saturday with illegal possession of secret documents, to betray the man who trusted him?
Was it money? Probably not.
Gianluigi Nuzzi, the Italian journalist who revealed some of the leaked documents alleging corruption in the Vatican and internal conflict over the role of the Vatican bank, declines to reveal his sources but insists he gave no money to them.
Nuzzi, a respected journalist with a good track record whose book "His Holiness" contains some of the allegations, says those who gave him the documents were devout people "genuinely concerned about the Catholic Church" who wanted to expose corruption.
The 46-year-old Gabriele, facing up to 30 years in prison if convicted, lives in a comfortable apartment in the Vatican with his wife and three children, and is said by all who knew him to be very religious.
While Vatican employees do not receive large salaries, they do enjoy benefits such as low rent, no income tax, and cheap food and petrol at the commissaries of the 108-acre city-state.
On papal flights, the handsome, clean-cut Gabriele rarely came into the press section. When he did, he was polite to journalists but resisted any attempt to squeeze information out of him.
A priest who knows Gabriele told the newspaper La Stampa on Saturday that he was "a man of simplicity" who would not have been able to organise a campaign of leaks.
"Why would he risk the good family life he built?" the priest, who was not identified, told the newspaper's Vatican affairs writer, author Andrea Tornielli.
MOTIVE A MYSTERY
Indeed, as in any good mystery, the question on many people's minds is: What was the motive?
If the whistleblower really is the man who helped the pope dress, served his meals, and rode next to the driver of the 'popemobile' in St Peter's Square, could he have done it on his own?
Many commentators doubted it, and some speculated that he may have been a pawn in a larger, internal power struggle, the words "scapegoat", "plot" and "conspiracy" tripping off their tongues.
Some commentators have said that the Machiavellian machinations that have come to light recently are part of a campaign of reciprocal mud-slinging by allies and enemies of the Vatican secretary of state, Cardinal Tarcisio Bertone.
"This is not just a leak of documents that can be defined as a betrayal," Church historian Alberto Melloni wrote in the Corriere della Sera newspaper, saying it was part of a power struggle among cardinals in the Curia, the Vatican's central administration.
"This is a strategy of tension, an orgy of vendettas and pre-emptive vendettas that has now spun out of the control of those who thought they could orchestrate it," Melloni said.
Another Church historian, Vittorio Messori, who wrote books with Benedict before he was elected pope in 2005, told La Stampa: "The Curia has always been a nest of vipers."
It remains to be seen if the papal butler, if he is guilty, was a lone idealistic whistleblower, or a victim of that nest.
(Reporting By Philip Pullella; Editing by Kevin Liffey)