The statistics for 2011-12 show a dramatic increase over the 171 priests removed between 2008 and 2009, when the Vatican first provided details on the number of priests who have been dismissed.

"The document shows that in two years alone, from 2011 to 2012, as 800 new cases of abuse came into the Vatican for review, the Pope actually defrocked 400 priests and the Vatican sent another 400 cases to either be tried by a Church tribunal or to be dealt with administratively," said Rome Acting Bureau Chief and Vatican Correspondent Nicole Winfield.

The file was part of a Vatican data collected for a UN hearing on Thursday.

Church officials at the hearing in Geneva faced a barrage of hard questions covering why they were withholding the information and what they were doing to prevent future abuse by Catholic priests.

Victims' advocates complained that there was still too little transparency.

Pope Benedict, who was elected in 2005, took the helm as the scandal of child sex abuse by priests was breaking.

The maximum penalty for a priest convicted by a church tribunal is essentially losing his job: being defrocked, or removed from the clerical state.

There are no jail terms or any other penalties by the Catholic Church to prevent a cleric offender from raping again.

RA/MB