Irish Justice Minister Dermot Ahern has urged anybody who witnessed institutional child sex abuse to come forward with evidence that could help secure criminal prosecutions.
Victims and those who have any information on the catalogue of sexual, physical and emotional brutality suffered by thousands of children for decades at so-called industrial and reformatory schools should contact the Garda, he insisted.
Mr Ahern was speaking after President Mary McAleese called for the criminal prosecution of the perpetrators detailed in last week's Ryan report.
He said the help of witnesses could be critical to charges being brought.
"I would urge as many people as possible to co-operate in helping convict perpetrators who have yet to face justice to come forward," he said.
"I know it is very difficult for them but the Garda are there to help and build evidence for future prosecutions.
"There are some who witnessed evil being done and who may have vital information to offer. Their help even at this late stage could prove pivotal in grounding future prosecutions."
Mr Ahern said the abuse crimes, mainly carried out by members of religious orders who ran schools for the state, are so enormous that they can't be swept under the carpet.
"As a nation we must try and come to terms with it but from a legal point of view there are procedures and there's a court system," he said.
Assistant Commissioner Derek Byrne, who was appointed to investigate the clerical child abuse, has set up a helpline for witnesses to come forward.
Anyone with information can contact the detectives during office hours in the Garda Metropolitan HQ in Dublin's Harcourt Square on 00353 (0)16663612.
Victims and witnesses can also write to the Assistant Commissioner, National Support Services, Harcourt Square, Dublin 2 with correspondence marked Ryan Report.
© Press Association