VATICAN CITY (Reuters) - A saddened Pope Benedict marked a difficult Pentecost Sunday as the Vatican braced for a possible widening of the scandal that has seen his butler arrested on charges of stealing private documents in the "Vatileaks" affair.
The pope looked weary as he celebrated a mass in St Peter's Basilica to mark the day when the Church teaches that the Holy Spirit descended on Christ's apostles, or disciples.
Although the day is regarded as the birthday of the Church, earthly celebration was likely to be far from the minds of the 85-year-old pope and the cardinals who flanked him at the basilica's papal altar.
On Saturday his personal butler, Paolo Gabriele, 46, was formally charged with stealing confidential papal documents.
The pope made no reference during his two public appearances on Sunday to the scandal or the arrest, which aides said had "saddened and pained" him.
But Cardinal Carlo Maria Martini, the former archbishop of Milan and himself once a candidate for the papacy, seemed to speak for many when he said the scandal should prompt the Church "to urgently win back the trust of the faithful".
The atmosphere in the walled city-state was glum as Vatican sources said they could not rule out more arrests, particularly if Gabriele named any accomplices.
Gabriele is suspected of leaking highly sensitive documents, some of which allege cronyism and corruption in Vatican contracts with Italian companies.
The scandal, which has been brewing for months, has now hit the very heart of the Roman Catholic Church because Gabriele - now known in Vatican statements as "the defendant" - was until Wednesday night the quiet man who served the pope's meals, helped him dress and held his umbrella on rainy days.
PERSONAL BETRAYAL OR BIGGER PLOT?
Cardinal Martini, writing in an Italian newspaper, said the pope had been "betrayed" just as Jesus was betrayed 2,000 years ago, and that the Church would have to emerge from the latest scandal cleaner and stronger.
Still, few believed that Gabriele, a shy and private man, could have acted on his own and some said he may have been an unwitting pawn in a Vatican power struggle.
"Either he lost his mind or this is a trap," a friend of Gabriele's in the Vatican told the newspaper La Stampa.
"Whoever convinced him to do this is even more guilty because he manipulated a simple person."
While news of Gabriele's arrest has filled pages and pages of newspapers in Italy and beyond, the Vatican's own newspaper, L'Osservatore Romano, has ignored the story.
Some say this may be because the paper itself has been an instrument in a power struggle involving reciprocal mud-slinging between allies and enemies of the Vatican's "prime minister", Secretary of State Cardinal Tarcisio Bertone.
"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," Church historian Alberto Melloni wrote in the Corriere della Sera newspaper.
The scandal involves the leaking of a string of documents to Italian media in January and February, including personal letters to the pope.
They included letters by an archbishop who was transferred to Washington after blowing the whistle on what he saw as a web of corruption and cronyism; a memo that put a number of cardinals in a bad light; and documents alleging internal conflicts about the Vatican Bank.
On Thursday night the Italian president of the Vatican Bank, Ettore Gotti Tedeschi, was ousted by the board of external financial directors.
He said he was paying for his efforts to make the bank more transparent, but board members said he had been an ineffective, incompetent and divisive manager.
(Reporting By Philip Pullella; Editing by Kevin Liffey)