One of the most notorious priest abusers to come to public attention in Ireland was Fr Eugene Greene of Raphoe diocese.
He was jailed for 12 years at Donegal Circuit Court in 2000 when he pleaded guilty to 41 sample charges of sexual assault against 26 children in Donegal parishes between 1965 and 1982.
He had been charged on over 100 counts. The trial heard that many of his victims were altar boys, who suffered repeated assault and buggery. Sentencing him, Judge Matthew Deery noted some of his victims had turned to drink to try to erase the pain of their childhood abuse which he described as "horrific".
In 2001 Greene sought a reduction in his sentence at the Court of Criminal Appeal on grounds of advanced age and a drink problem; the appeal was dismissed. He was released in 2008 after serving nine years.
A native of the Annagry parish in Co Donegal, Greene had served 10 years with the Kiltegan Fathers in Nigeria when he returned to Ireland in 1965. He then served in Scotland and Cork.
In 1970 he was curate in Gweedore, thereafter serving in Killybegs, Lettermacaward, Gorthahork (where between 1976 and 1981 he abused 16 boys) Glenties, Kilmacrennan and Annagry.
His abuse came to light when he reported a man for trying to blackmail him. In the subsequent investigation, the Garda uncovered the abuse.
In their 2008 book Breaking the Silence retired garda Martin Ridge and journalist Gerard Cunningham revealed that Greene's criminal activities "were known to Raphoe clergy at least as early as 1976".
Bishop Séamus Hegarty, who was bishop of Raphoe from 1982 to 1994, has said Greene was sent to the Stroud treatment centre in England because of alcoholism but that he was unaware while he was bishop of the diocese of any allegations of sexual abuse against the priest.
Dr Hegarty became bishop of Derry in 1994 and resigned last week for health reasons.