Management at Gormanston College was aware of abuse perpetrated by Fr Ronald Bennett but did not remove him from his post, it has emerged.
Complaints were made against the Franciscan priest in 1973 to a member of management at the college in Co Meath by the parents of one of the boys he abused. The parents were given assurances that the priest would no longer be allowed to be alone with boys, but he continued abusing until 1981.
Bennett was yesterday given a five-year suspended sentence after pleading guilty to six sample charges of indecent assault of boys at the college.
The boys abused by him were summoned to his office over a tannoy system and waited outside until a set of "traffic lights" turned to green and signalled that they could enter.
He gave sex education to the boys, held their pocket money until they needed it and also allocated sports clothes at the college.
Franciscan provincial Fr Caoimhín Ó Laoide OFM said that at the time the feeling had been that there could be an internal solution to the problem.
"From this point looking back, there was misguided thinking that it could be dealt with internally," he said.
He acknowledged that if the assurances given to parents in 1973 had been adhered to, a lot of other boys would not have suffered. He said there were now robust procedures in place.
"We acknowledge the hurt caused and our concern is for the injured parties," he said. "There is a tremendous sense of sorrow."
He added that the religious order had an open-door policy and any former pupil could contact them at any time.
In court yesterday Judge Desmond Hogan praised the order for its recent handling of the priest, saying it behaved "most responsibly in the circumstances". He added: "He is practically under open house arrest as it is and I do not wish to interfere with that."
One in Four, the support group for people who have experienced sexual abuse, says it is disappointed and concerned by the sentence, particularly by the reasons for its mitigation.
Colm O'Gorman, director of the charity, called on the Director of Public Prosecutions to review the case to see if the sentence could be appealed.
"A person in significant authority used his authority to sexually abuse and assault children," he said.
"It is difficult to understand how a custodial sentence could be avoided. The passage of time doesn't minimise the heinous nature of sexual assault on a child."
Richard Lanigan, a past pupil of Gormanston College, said the priest's behaviour was common knowledge among the boys in the 1970s, although they were not aware of the extent of the abuse.
"Some of the priests were lovely men, dedicated to their students," he said, "but this went on and adults who should have known better didn't want to go there. The neglect of these children by the other priests is every bit as bad as what Bennett did to them."
Mr Lanigan has set up a website to provide an independent forum for former students to discuss how abused past pupils might be supported.