Hundreds of cases of child sex abuse going back decades may be reopened after the Catholic Church publicly abandoned a controversial practice known as blind reporting.

Key points: Organisations reported abuse but removed name, meaning police unable to investigate

Organisations reported abuse but removed name, meaning police unable to investigate Over past eight years, NSW Police received 1,476 blind reports

Over past eight years, NSW Police received 1,476 blind reports Many reports relate to Catholic Church

Many reports relate to Catholic Church Child abuse victims are now speaking out

Blind reporting occurs when an organisation passes on an allegation of child sex abuse, but strips the report of the name of the victim, meaning police are unable to investigate the report.

NSW Greens MP David Shoebridge has obtained documents under Freedom of Information (FOI) laws that, for the first time, reveal the extraordinary extent of blind reporting, which has potentially allowed hundreds of perpetrators to continue to abuse children.

The ABC has spoken to child sex abuse victims who are angry the allegations they reported to the Catholic Church some years ago were never fully reported to police.

The figures obtained by Mr Shoebridge reveal during the past eight years, NSW Police have received 1,476 blind reports from NSW organisations.

Many relate to the Catholic Church.

"The blind reporting process has at its heart a really obscene conflict of interest," Mr Shoebridge said.

"One of the key problems with blind reports is that the police's own protocol says when they get a blind report they don't investigate it.

"They just file it as criminal intelligence and that means perpetrators are not being brought to justice."

The practice has also attracted criticism from the NSW Ombudsman.

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Deputy Ombudsman Steve Kinmond warned: "We could have over a thousand reports that may be on the wrong side of the law."

The NSW Police have refused to reveal whether they still actively encourage blind reporting, despite a recommendation from the NSW Police Integrity Commission last year that the practice should be reviewed.

The FOI documents show there was a huge increase in the numbers of blind reports passed to police since the start of the Royal Commission into Institutional Responses to Child Sexual Abuse.

The royal commission today held a public roundtable to examine the lawfulness of the longstanding practice of blind reporting.

Between 2005 and 2009, a total of 53 blind reports were passed on by organisations to the NSW Police sex crimes squad.

In 2012, that number increased to 256 blind reports, and by 2013, organisations passed on 460 blind reports to police.

The commission heard the controversial practice was still commonplace.

Detective Superintendent Linda Howlett, head of the Sex Crimes Squad, indicated police continue to facilitate blind reporting under protocols revised in 2014.

Victim's statement never passed on to police

Victims of child sex abuse are now speaking out against blind reporting.

One of those victims, who wants to be known only as Denise, is the niece of notorious paedophile Denis McAlinden, whose crimes were concealed by the Catholic Church for decades.

She reported child sex abuse at the hands of her uncle to the Catholic Church in 1995, but her signed statement was never passed on to police.

A sex abuse victim, known as Robert, as a child. ( Supplied )

In 2008, her allegations were included in a blind report, but Denise was never contacted.

"I feel really let down," Denise told the ABC.

"I think what I've been through, I've done everything I can to help report things, and nothing was done.

"It was the Church protecting their own as far as I'm concerned."

Another victim, known as Robert to protect his identity, reported child sex abuse to the Catholic Church in 2011.

He said he was told the allegation would be passed to police, but instead, a blind report was lodged which did not contain his name.

"Blind reporting I think should be against the law," Robert said.

"What's the point of telling the police about an allegation without giving them the full information so that they can't investigate?"

Majority of blind reports not investigated

Last year, the Police Integrity Commission launched Operation Protea, established after the ABC's Lateline program revealed the practice of blind reporting.

Blind reporting has been standard practice in NSW for up to two decades.

The FOI documents reveal that the NSW Police sex crimes squad was struggling to cope with the volume of blind reports it was receiving by 2014, following a major focus on child sex abuse during a special commission of inquiry and the royal commission.

In July 2014, NSW Police drafted a new protocol to lay out the procedure to be followed by organisations like the Catholic Church, the Anglican Church, the Salvation Army and others when reporting historical child sex abuse in blind reports.

Robert says blind reporting should be illegal. ( Supplied )

The document states: "Since the commencement of 2014 the [number] of these 'blind reports' has continued to increase ... with competing priorities within the squad, none of these 2014 reports have been assessed or allocated to any Sex Crimes staff for action.

"The NSWPF may be open to criticism if this backlog is not addressed."

The document shows that the new protocol stipulated that Local Area Commands should now take charge of blind reports, but in the overwhelming majority of cases, no investigation results from blind reports.

The practice of blind reporting was criticised in a report by the Police Integrity Commission last year, which recommended the NSW Police review the practice.

But the NSW Police Force is refusing to clarify its position on blind reporting, saying it cannot comment on a matter that is currently before the royal commission.

Mr Shoebridge says that is not good enough.

"What is clear from the most recent bundle of documents out of the police is that the police are committed to blind reporting even though it's got such a clear conflict of interest," he said.

"How on earth the NSW Police think this is acceptable is a mystery."

Over a thousand reports 'could be on wrong side of law'

Mr Kinmond also holds concerns about blind reporting.

The NSW Ombudsman's office has lodged a submission with the royal commission, highlighting the practice of blind reporting serious indictable offences "is inconsistent with section 316 of the NSW Crimes Act".

"The act says you can't withhold information unless you have a reasonable excuse. The real question is what constitutes a reasonable excuse," Mr Kinmond said.

"We could have over a thousand reports that may be on the wrong side of the law.

"This is about protecting those who come forward but it's also about protecting children — we need to strike the right balance."

The Catholic Church said its Professional Standards Office and local dioceses have, since midway through last year, abandoned the practice of blind reporting, and is retrospectively lodging reports with police that pass on victims' names.

But the figures released by NSW Police show there were 109 blind reports lodged last year, and four so far this calendar year.

It is not clear whether any of those reports came from the Catholic Church.

Chief executive of the church's Truth, Justice and Healing Council, Francis Sullivan, said the church had responded to the Police Integrity Commission's report in reviewing its practice on blind reporting.

He expressed regret if victims felt aggrieved by the process of blind reporting.

"It's absolutely regrettable if people were under the impression that their name was going to be given to the police and it wasn't," Mr Sullivan said.

"The practice now is that regardless of individual preferences, the name of the perpetrators and the names of victims are given to the police."

The Catholic Church said it had so far re-lodged 250 reports of alleged child sex abuse to police, which had previously been blind reported.

"These re-lodgements are continuing all the time," a spokesperson said.