Ms Stern said there were several issues with the processes of dealing with complaints within the group. 

These included the procedure known as "blind reporting", which involved some aspects of an abuse complaint being reported to the police by the group, but without all information, and without any information identifying the complainant. 

These blind reports were effectively filed away and not investigated by police, the commission heard. 

Police did not investigate whether victims who were the subject of blind reports knew that this meant there was unlikely to be an investigation. 

The commission heard that police officers who participated in regular PSRG meetings might have been aware the group was withholding information about serious criminal offences from other police, such as tapes of interviews with victims and medical evidence of abuse.

"It must have been apparent to the PSRG members, including [Inspector Cullen], that a variety of different forms of documentation and information was held by the Catholic Church by reason of the Towards Healing processes," Ms Stern said.

"One question to be considered ... is whether or not, to the knowledge of officers of the NSWPF, information which may well have been of material assistance in securing the apprehension or conviction of an offender was withheld by the Catholic Church from the NSWPF, and whether or not the NSWPF in fact encouraged or condoned this state of affairs." 

Ms Stern said the commission needed to consider whether Inspector Cullen's actions constituted police misconduct or whether she might be guilty of concealing a serious indictable offence.

She said the public hearing would also examine whether various police officers condoned or helped establish procedures whereby important information about abuse was not communicated to the police force and whether this amounted to misconduct. 

The hearing continues.