One of Melbourne's most senior Catholic clergy has admitted children were put at risk after a priest failed to report allegations of child molestation made against a colleague.
The church apologised to the victim after Desmond Laurence Gannon was jailed for 25 months on Wednesday for molesting an altar boy on three occasions between 1968 and 1969.
Gannon, 79, had told the Victorian County Court he was giving the boy an anatomy lesson.
The victim, who is now in his 50s, says he told another priest at a Melbourne parish where Gannon was serving in 1989 or 1990 about the abuse, but was ignored.
"The priest came out (to the victim's house) and talked to me and all he did was he said: 'It is a while ago and let's forget all about it'," the victim told AAP.
"That was the last I heard from him."
He said he was disgusted by the priest's attitude.
"The Catholic Church must have known," he said.
"They are as guilty as he is, I reckon."
Vicar General of the Catholic Archdiocese of Melbourne Monsignor Les Tomlinson conceded the failure by the priest to disclose the abuse put children at risk.
"I suppose that is an obvious consequence, yes," Monsignor Tomlinson said.
"At any stage it is deeply regrettable that for whatever reason a person to whom's notice these matters are brought fails to act on it, because that means the situation isn't dealt with."
Gannon pleaded guilty to five counts of indecently assaulting a male under 16.
The court heard the abuse began in 1968 when the boy was an 11-year-old student at St Patrick's Primary School in Kilmore, north of Melbourne.
The priest drove the boy to a bush track where he removed the boy's pants and underpants and said "this is your penis".
He also kissed and fondled the boy.
Gannon later fondled the boy as he was putting on his robes prior to assisting him celebrate Mass and in the pump room of a local swimming pool, the court heard.
Asked by police why he took the boy to the secluded bush location and touched his penis, Gannon replied he was explaining the "differences in anatomy".
Wednesday's prison sentence is Gannon's second. He was jailed for 12 months in 1995 - and received suspended sentences - after being found guilty of molesting boys at Victorian parishes between 1958 and 1976.
Sentencing Gannon, Judge Frank Gucciardo said the former priest had demonstrated a lack of remorse and empathy.
"This was a well-warn, thought-out routine, even on your own say so, with sex education a poor excuse," he said.
"You ceased offending after the realisation that other priests were being convicted and sentenced, and that provided a strong incentive to desist."
Monsignor Tomlinson apologised to the victim on behalf of the church.
"We are sorry, yes," he said.
"We deeply regret the actions of Father Des Gannon."
The victim urged others who have been abused to come forward.
"A lot more people are willing to help and listen now and not just shove it under the carpet," the victim said.
He said that instead of fulfilling his childhood ambition of being a policeman, he became a juvenile delinquent after the abuse.
Judge Gucciardo ordered Gannon, of Box Hill, serve 14 months before being eligible for parole.