Rome - Campaigners have called on Pope Francis, who was elected in March, to make tackling the issue of sexually abusive priests an urgent priority of his papacy.
The UN's Committee on the Rights of the Child released its demands for information from the Holy See on Tuesday.
The committee said that "in the light of the recognition by the Holy See of sexual violence against children committed by members of the clergy, brothers and nuns in numerous countries around the world, and given the scale of the abuses", the Vatican should provide detailed information on all cases of child sexual abuse committed by clergy.
The Vatican was told to show whether it had implemented measures "to ensure that no member of the clergy currently accused of sexual abuse be allowed to remain in contact with children," amid claims from around the world that bishops often moved abusive priests from one parish to another.
The UN committee demanded to know about specific cases in which bishops or other Catholic leaders had failed to report suspected abuse to the police.
The Vatican was also urged to divulge details of its investigation of alleged sexual abuse and the outcome of those investigations, including any financial compensation or psychological counselling for victims.
The committee wants to know what measures the Holy See has taken "to prevent further sexual violence from taking place in institutions run by the Catholic Church." The Vatican has until January to compile all the information, in time for an open meeting of the UN committee in Geneva at which Vatican officials will be questioned.
Despite being a signatory to the UN Convention on the Rights of the Child, the Holy See had largely ignored requests for information, said Keith Porteous Wood, the executive director of the National Secular Society, who gave evidence to the committee last month.
"One of the requirements of a signatory is to compile a five yearly report on compliance – or in the Vatican's case non-compliance – with the convention. The Holy See has grossly failed to do this for something like 12 years," he told The Daily Telegraph."They allowed sexual abuse on an unbelievable scale and it hasn't all come out yet – we expect many, many more cases to emerge in the developing world."
Pope Francis's apparent determination to crack down on allegations of corruption and money-laundering within the Vatican bank gave hope that he might take a tough line on sexually abusive clergy, Mr Porteous Wood said.
"I think it's a good sign," he said. "Child abuse is a major issue, along with corruption, that he needs to sort out. His legacy will be judged, I think, on his ability to deal with these immensely difficult problems."
Geoffrey Robertson QC, the human rights lawyer, who has strongly criticised the Catholic Church's cover-up of sex abuse scandals around the world, said: "The committee's enquiries will inevitably lead it to conclude that the Vatican has broken multiple articles of the convention on a huge scale in many countries. The result in human suffering is incalculable.
"Francis's papacy could well be defined by the world's verdict on his response - more handwringing apologies or calls for a line to be drawn under the past will no longer wash.
"He will fail unless he initiates bold tangible actions, for example lifting the veil of secrecy that has protected so many clerical rapists, engaging secular authorities and offering rather than resisting appropriate compensation."