O'Grady was filmed in an unnamed Dublin park near where he lived last year and, according to the film makers, went unchecked by the gardai.

O'Grady served seven years for the sex crimes he committed for more than two decades in his Californian parishes and on his release he was excommunicated and deported to Ireland.

He has now served his sentence but there must be real concerns that he . . . and other child sex abusers . . . are not monitored after their release.

This is not to argue that we need the sort of widely hyped 'Megan's Law' that has been adopted in California, which ensures that local people are informed if a convicted paedophile moves into their area. This is a charter for vigilantes and has not been proved to protect children.

But the experience of Liege in Belgium, where a known paedophile is being held on suspicion of the kidnap and murder of two stepsisters Stacy Lemmens, 7, and Nathalie Mahy, 10, must surely mean we err on the side of caution.

O'Grady himself wanted to go on the record because he is angry that, instead of confronting him, the church simply moved him from parish to parish, where he became a serial abuser.

The question now is what sort of monitoring, controls . . . and psychological supports . . . have been put in place here to ensure that child sex offenders who have been released from prison and are now living in the community are prevented from ever harming children again.