A UN committee has asked the Australian government to explain its response when Cardinal George Pell backed a Vatican refusal to hand over documents to the child abuse royal commission.

The committee meeting in Geneva this week is considering Australia's fourth report on human rights and the country's implementation of the Convention against Torture.

It has received several submissions from non-government organisations in Australia including two from networks representing survivors of institutional and clerical child abuse.

Geneva members of the Committee Against Torture raised the issue of Cardinal Pell's defence of a Vatican decision not to hand over all documents relating to child sex abuse by clerics in Australia.

At a public hearing of The Royal Commission into Institutional Responses to Child Sexual Abuse in August, Cardinal Pell told commission chair Peter McClellan his request for all papal documents relating to every abuse case involving an Australian cleric was "unreasonable".

Cardinal Pell who was giving evidence by video link from the Vatican said the documents pertained to "the internal workings of a sovereign state".

Australian Government representatives were asked by the UN committee for their response to this refusal to comply with legal requests for information necessary for the Royal Commission to do its job.

The committee has heard submissions from Care Leavers Australia Network (CLAN) and from the group Survivors Network of those Abused by Priests (SNAP), which outlined cases of child sexual abuse in Australia which were covered up or ignored by church and state authorities.

Nicky Davis who heads SNAP in Australia said in a statement that Cardinal Pell promotes himself as being prepared to 'co-operate fully' with the royal commission, his actions tell a different story.

SNAP has complained that Australian politicians seem unconcerned about the Vatican's blocking of the investigations and called for Government action to ensure all requested documents are turned over to the royal commission.

Australia will respond to the questions put by the committee at 1am on Wednesday Australian time.

In its 51-page report to the Committee Against Torture, which was submitted in 2012, the Australian government does not address the issue of institutional child sexual abuse or mention the Royal Commission, which was announced at the end of 2012.