Pope Francis has admitted that clerics have sexually abused nuns, and in one case they were kept as sex slaves.

He said in that case his predecessor, Pope Benedict, was forced to shut down an entire congregation of nuns who were being abused by priests.

It is thought to be the first time that Pope Francis has acknowledged the sexual abuse of nuns by the clergy.

He said the Church was attempting to address the problem but said it was “still going on”.

Last November, the Catholic Church’s global organisation for nuns denounced the “culture of silence and secrecy” that prevented them from speaking out.

The Pope’s comments come amid long-running cases of sexual abuse of children and young men by priests at the Church.