Pope Benedict XVI, leader of the world's 1.2 billion Catholics, has told Australians he is deeply sorry for the sexual abuse of children by some Catholic priests and has said that those responsible must be brought to justice.

Dr Rowan Williams has expressed his "deep sorrow" over mistakes made by the Church of England in the Peter Halliday child abuse case, affirming its tough policy and calling for vigilance.

After the jailing of a choirmaster for sexual abuse against children in the 1980s, the Church of England says that the mistake of failing to report an abuser to the police would not happen now. But the case highlights the need for extra vigilance and robust child protection policies.

Amid accusations that it has failed to act properly in abuse cases stemming from the past, the Church of England has made child safety a priority. Its current policies and procedures are demonstrably rigorous and caring, it says.

A network of sexual abuse victims' advocates originally set up to challenge the Catholic Church in the USA has started to pressure the president of the Southern Baptists, America's largest Protestant denomination, to take action against abusive ministers and elders in its ranks.