The teacher, Thomas Keady, had been running a ‘‘mobile amusement business’’ for five or six years at the time of the Sandy Hollow assault in 1994, newly released court records show.

Keady, then 67, who had already spent two years in a Victorian jail in the early 1960s for child sex offences, had constant access to Hunter and Central Coast children who used the jumping castles, merry-go-rounds, laughing clowns and food vending machines in the early 1990s.

The news has outraged Salt Ash man and Keady victim Rob Roseworne, who has spent three years trying to hold the Catholic Church to account for its failure to report Keady to police in 1979 after multiple child sex claims.

‘‘How many children did Keady sexually abuse for all those years after the church knew he was an offender but did nothing?’’ Mr Roseworne said.

He has renewed calls for the Director of Public Prosecutions to take action against former St Patricks College principal Brother Anthony Whelan, who sacked Keady in 1979 after four boys said Keady had sexually abused them on a trip away from the school.

Brother Whelan retired this year as Central Coast Catholic Schools director. In a Catholic Church investigation prompted by Mr Roseworne’s complaint in 2010, Brother Whelan said he sacked Keady, advised the boys to tell their parents, but did not report the matter to police.

The DPP advised Sutherland police in April against charging Brother Whelan for misprision of felony (concealing serious crime) offences despite noting ‘‘there would appear to be a prima facie case against Whelan’’.

‘‘Such a prosecution would not be in the public interest,’’ the DPP told Sutherland detectives.

Court records of Keady’s 1994 conviction at Wyong Local Court show he lived at Blue Haven at the time of the offences, but indecently assaulted one of two brothers while on a camping trip at Sandy Hollow on October3 of that year.

Keady asked the boy, ‘‘Do you mind if we do something naughty?’’ before indecently assaulting him. The boy and his brother fled from the area and rang police and their parents from a service station.

Keady did not deny the incident but said he was intoxicated. He was placed on an 18-month good behaviour bond and died in 2012.

Mr Roseworne said Brother Whelan ‘‘looked at the little picture’’ in 1979 in sacking Keady, but ‘‘failed to consider the bigger picture of protecting children’’.

‘‘Do I believe Keady had other victims? Absolutely,’’ he said.

He had registered to give evidence to the Royal Commission into Institutional Responses to Child Sex Abuse about the church’s handling of the Keady case, and the DPP’s advice to police.

‘‘The DPP has said it’s not in the public interest to charge Whelan. I think the average Joe Blow in the street might take a different view to the DPP.’’

Greens NSW Upper House MP David Shoebridge said it was a clear case where the failure to report Keady to police had left children at risk.

‘‘It’s not a victimless crime, and the failure to report to police exposes many children to the terrible damage caused by child sexual abuse,’’ Mr Shoebridge said.

‘‘It’s about time the DPP realised that.’’

A DPP spokeswoman said it did not comment on matters referred to it by police.