|Relations between Catholics and Anglicans were strained by the Vatican offer of conversion [GALLO/GETTY]
The Vatican refused to help an Irish investigation into child sex abuse by Catholic priests because the requests were seen as "an affront to Vatican sovereignty," leaked diplomatic cables have shown.
The documents, which were released to the UK's Guardian newspaper by the WikiLeaks website, reveal that the Catholic Church blocked its officials from testifying before an Irish commission because the request was not made through official channels.
A classified dispatch from the Vatican's embassy in the US said that the church received requests from the Murphy commission in 2009 but did not comply, instead insisting that communication with the inquiry took place through diplomatic channels.
"The Murphy Commission's requests offended many in the Vatican," the cable says.
"Vatican officials were also angered that the government of Ireland did not step in to direct the Murphy Commission to follow standard procedures in communications with Vatican City."
"Adding insult to injury, Vatican officials also believed some Irish opposition politicians were making political hay with the situation by calling publicly on the government to demand that the Vatican reply."
In the end, the Vatican secretary of state - the equivalent of a prime minister- wrote to the Irish embassy and demanded that any further requests come through diplomatic channels.
Noel Fahey, the Irish ambassador to the Vatican, told a US diplomat that the fallout from the commission's investigations was "the most difficult crisis he'd ever managed".
The Murphy commission's findings, published in November 2009, caused shock across Ireland and the worldwide Catholic community by detailing how Church authorities covered up for paedophile priests in Dublin for three decades.
Pope Benedict met with Ireland's two most senior Catholic churchmen after the publication of the Murphy report, and said he shared "the outrage, betrayal and shame" felt by Irish Catholics over its findings.
Also revealed in the cables are the UK's fears that the pope could have unwittingly sparked violence in Britain by inviting disaffected Anglicans to convert to Catholicism.
Francis Campbell, the UK ambassador to the Vatican, told US diplomats that the pontiff's offer for a mass conversion of Anglicans opposed to women clergy had plunged Anglican-Vatican relations into "their worst crisis in 150 years", the cable says.
Campbell said that after the pope decided to announce special dispensation allowing Anglicans to convert en masse while maintaining some of their traditions, dialogue between the two churches changed "from true unity to mere co-operation".
Rowan Williams, the Archbishop of Canterbury and leader of the Anglican church, had been put in an "impossible situation" by the offer, the cable says, noting that if he reacted forcefully he would damage relations between the churches, but by not reacting, he would lose legitimacy in the eyes of his angry flock.
Worse, the offer could have sparked an anti-Catholic backlash in the UK, Campbell tells the US.
"The crisis is worrisome for England's small, mostly Irish-origin, Catholic minority. There is still latent anti-Catholicism in some parts of England and it may not take much to set it off."
"The outcome could be discrimination or in isolated cases, even violence, against this minority," he said.
In the cable, the US mission to the Vatican wonders whether the pontiff's offer was worth it, "especially since the number of disaffected Anglicans that will convert is likely to be a trickle rather than a wave".
So far, three Anglican bishops and about in 50 priests have announced they will switch to Catholicism in protest at female priests.
In September, the pope and Williams used the pontiff's state visit to Britain to make a symbolic show of unity by holding joint prayers.
The cables also reveal that the Vatican has been opposed to Turkey joining the EU. The Catholic leadership were reportedly concerned that the accession of a Muslim country to the political bloc would undermine Europe's "Christian roots".