Michael and Trisha Day, whose son Paul was one of 39 victims of sadistic pedophile priest John Denham, said they wanted to remind the congregation that Father Brennan's 50 years as a priest included a criminal conviction related to Denham's offending.

"If we hadn't come here today it would have been as if we condoned what he did," Mrs Day said.

Father Brennan was convicted of making a false written statement that he did not recall parents, students and teachers complaining about Denham's sexual abuse while Father Brennan was principal of St Pius X at Adamstown.

He was sentenced to a 12-month good behaviour bond. A District Court judge rejected his appeal in August last year, saying he did not believe Brennan did not recall the complaints.

In Sacred Heart Cathedral yesterday Bishop Michael Malone told the congregation that people had a right to protest, but requested that they do it "quietly and unobtrusively".

Police were called after Mrs Day walked into the church with her placard, but left after speaking to protesters.

During the ceremony three women approached Mr and Mrs Day to express their sorrow about the sexual abuse.

Outside the church Bishop Malone, a number of priests and parishioners spoke to the protesters.