Vatican sex abuse scandal explained - in 60 seconds
5 February 2014 Last updated at 18:43 GMT
The UN has called on the Vatican to "immediately remove" all clergy who are known or suspected child abusers.
It denounced the Holy See for adopting policies which allowed priests to sexually abuse thousands of children, and criticised its attitudes towards homosexuality, contraception and abortion.
The Vatican responded by saying it would examine the report - but also accused its authors of interference.
BBC News looks into the background of the crisis - in 60 seconds.
Video produced by Michael Hirst