Christopher Cosgrove, of Ballyhaunis Road, Claremorris in Co Mayo, pleaded not guilty to the offences committed against six boys at St John's National School in Sligo in the 1960s and 1970s.

Cosgrove was a Marist brother at the time and taught as Brother Christopher.

At Sligo Circuit Court today, Judge Anthony Kennedy said the number of offences was enormous and the cumulative effect of them gave this case its great seriousness.

During five days of evidence the court heard that the former teacher had operated a reign of terror in class and the impact on his victims included attempted suicide, alcoholism and disruption to family relationships.

Sentencing, Judge Kennedy said the offences were planned and protracted and committed against defenceless victims whose access to justice was impeded by Cosgrove.

The judge said Cosgrove must be punished and others deterred. He also ordered that his name be put on the sex offenders' register indefinitely.