Mr Lena said he would suggest to the court that it should avoid using the religious nature of the relationship between bishops and the pope as a basis for civil liability because it entangles the court in an analysis of religious doctrine that dates back to the apostles.

"Courts tend to avoid constructing civil relationships out of religious materials," he said.

The lawyer behind the Kentucky case, William McMurry has alleged that the Vatican had clear and direct control over bishops, mandated a policy of secrecy, and is therefore liable for the bishops' failure to report abuse. He is seeking unspecified damages.

The Vatican defence will also include a response to claims that the 1962 document 'Crimen Sollicitationis' ('Crimes of solicitation') barred bishops from reporting abuse to police, said Mr Lena..

There is no evidence the document was even known to the archdiocese in question and it did not mandate that bishops not report abusive priests, said Mr Lena.

The confidentiality imposed by Crimen did not trump civil law and was applied only in formal canonical processes, which bishops had the discretion to suspend if there was a conflict with reporting laws, he said..

"It is important that people - particularly people who have suffered abuse - know that, contrary to what some plaintiffs' lawyers have consistently told the media, the canon law did not bar reporting of these crimes to the civil authorities," Mr Lena told the Associated Press.

The document describes how church authorities should deal procedurally with cases of abuse of children by priests, cases where sex is solicited in the confessional - a particularly heinous crime under canon law - and cases of homosexuality and bestiality.

Mr McMurry recently described the document as as "a smoking gun."

"It's evidence of a 'written' policy that demands no mention be made by a bishop of priest sex abuse," he said. "Since our case, and no other, is about holding the Vatican accountable for the bishops' failure to report to civil authorities, any policy that gags the bishop is relevant and material."

The Holy See is trying to fend off the first U.S. case to reach the stage of determining whether victims actually have a claim against the Vatican itself for negligence for the failure of bishops to alert police or the public about Roman Catholic priests who molested children.

The case was filed in 2004 by three men who claim they were abused by priests decades ago and claim negligence by the Vatican. Mr McMurry is seeking class-action status for the case, saying there are thousands of victims across the country. Mr McMurry also represented 243 sex abuse victims who settled with the Archdiocese of Louisville in 2003 for $25.3 million.

The Vatican is seeking to dismiss the suit before Pope Benedict XVI can be questioned or documents subpoenaed.

Its motion is being closely watched as the clerical abuse scandal swirls around the Holy See, since the court's eventual decision could have implications for a lawsuit naming top Vatican officials that was recently filed in Wisconsin and another one in Oregon is pending before the Supreme Court.

Mr McMurry has alleged that the Vatican had clear and direct control over bishops, mandated a policy of secrecy, and is therefore liable for the bishops' failure to report abuse. He is seeking unspecified damages.

McMurry has said that based on district and appellate court rulings, he does not need to prove bishops were employees of the Vatican but merely 'officials.' He pointed out that they take an oath of office. The pope appoints, disciplines and removes bishops.

If a bishop wants to spend more than $5 million he must ask permission from Rome, and if he wants to take a three-month sabbatical, he needs the Holy See's OK, said Mr McMurry's main expert witness, the Reverend Thomas Doyle, a canon lawyer who worked at the Vatican's U.S. nunziature.

END