They say that if a test case against an Irish diocese, probably Cashel and Emly, is successful, other cases will follow.

Manly & Maguire, a California law firm which has handled hundreds of clerical abuse cases, has said it is currently putting a test case together under Californian contract law. Other law firms are expected to follow suit after recent disclosures that 18 Irish priests are facing abuse charges in California.

According to attorney Patrick Wall, Manly & Maguire will argue Irish seminaries were hired by US dioceses to train priests and were negligent in their duties. He said the students in Irish seminaries were already "quasi-employees" of US dioceses and that the Irish seminaries had a legal duty to inform the US dioceses about any potential paedophiles.

Mr Wall said the first case would most likely be against the Archdiocese of Cashel and Emly, where Limerick paedophile Oliver O'Grady, who is the subject of 17 multimillion-dollar abuse lawsuits, was trained for Stockton diocese in California.

John Manly, a partner at Manly & Maguire, said he was "very confident" that in the event of successful court actions in the US, his firm could use an international treaty signed by Ireland and most EU countries to seize assets held in Ireland by the Irish dioceses.

"We know the exact provision of an international treaty we are going to use, but we can't release the details yet because we don't want to tip off the church in Ireland," he said.

He accused the church in Ireland of sending "ticking time bombs" to California and said that they must be accountable for their actions.

Mr Wall said his office would be hoping to show that the Irish dioceses were negligent in training the priests, had shown a failure to warn the US dioceses, and had failed to warn the Garda of the presence of paedophiles in their seminaries.

Mr Wall said there was strong evidence to suggest that some church authorities had known that O'Grady was a paedophile while he was still in St Patrick's Seminary in Thurles.

In May, the Stockton diocese paid out $3 million (€2.5 million) to a former altar boy who was abused by O'Grady.

The diocese has paid out a total of $14 million to victims of O'Grady, who pleaded guilty in 1993 to abusing two brothers.

O'Grady was deported to Ireland in 2000 after serving seven years in prison and is now living in Dublin.

In one civil deposition, O'Grady admitted sexually assaulting and molesting about 25 boys and girls from the 1970s up to the mid-1980s in various Stockton parishes.

A spokesman for the the Archdiocese of Cashel and Emly said last night that O'Grady, while not a priest of the archdiocese, had trained at St Patrick's Seminary in Thurles, which was under the patronage of the archbishop.

The spokesman, a former seminarian at St Patrick's, said he had never heard anything suggesting that O'Grady had such proclivities then, and the college authorities would never have allowed him be ordained if they had been so aware. It was "ridiculous" to suggest otherwise.

He said there were no diocesan records relating to O'Grady, though there would be records about him at St Patrick's.

He said O'Grady, as with other seminarians, was "adopted" by a US diocese and became a priest of the diocese he went to after ordination.