The Vatican is reported to have prepared and will soon publish a revision of the rules detailing how the Catholic Church handles sex abuse cases.

The revision would extend the statute of limitations for sex abuse crimes from 10 to 20 years and will classify child pornography as a ‘serious crime’, according to the website of the National Catholic Reporter.

Vatican spokesman Federico Lombardi declined to comment on the matter.

The ‘motu proprio’ document that currently outlines how the Vatican handles serious crimes was written by then-Cardinal Joseph Ratzinger before he became Pope Benedict XVI.

At the time he headed the Congregation for the Doctrine of the Faith, the Vatican's chief moral enforcer.

According to religious news agency, the new document could have been signed on 3 July after a meeting between the pope and Cardinal William Joseph Levada, the current head of the Congregation.

Revisions could include demoting paedohphile priests to lay status and forcing diocesan bishops to hand over guilty priests to civil authorities, said.

In April, the Vatican posted on its website the guidelines on handling paedophilia cases outlining similar measures.

The Catholic Church has been rocked by a string of abuse scandals in recent months.

Late last year, Ireland was rocked by two successive reports revealing widespread abuse mainly of boys by priests going back decades, coupled with the Church hierarchy's complicity in covering it up.

The pope issued a pastoral letter to Irish Catholics in March expressing shame and remorse for the revelations of abuse committed by those entrusted with the care of young people in Ireland, in cases stretching back decades.

The scandals snowballed with revelations in the pope's native Germany, Belgium, Austria, US, Brazil and other countries.

The pope has condemned paedophile priests several times, and met with abuse victims in Australia, the US and Malta.