The hearing is the Vatican's first since 2002, when it signed up to an international convention banning torture as well as cruel, inhuman and degrading treatment.
Victim support groups insist that the rape and molestation of children by the clergy and lay personnel falls under the terms of the convention.
They are hoping that the Vatican will face similarly-scathing criticism as it did in January when it came before a UN children's rights watchdog.
That panel condemned the Vatican for failing to do enough to stamp out abuse and for allowing systematic cover-ups around the glove, despite pledges to adopt a zero-tolerance approach.
The Roman Catholic Church has been shaken by a decade-long cascade of scandals involving child abuse by priests and Catholic lay officials, from Ireland to the United States and Australia.
Hundreds of predatory priests have been defrocked, but critics say Vatican action has been too slow and failed to stem the scourge of paedophile clergy.
Addressing the opening of the UN committee session on Monday, the Holy See's UN envoy Monsignor Silvano Tomasi said the Vatican lent the battle against torture "a crucial moral voice in its support through its teaching".
"It should be stressed, particularly in light of much confusion, that the Holy See has no jurisdiction over every member of the Catholic Church," he told the panel.
"The Holy See wishes to reiterate that the persons who live in a particular country are under the jurisdiction of the legitimate authorities of that country and are thus subject to the domestic law and the consequences contained therein," he said.
"State authorities are obligated to protect, and when necessary, prosecute persons under their jurisdiction."