A support group for victims of church-based abuse says the Catholic Church in Aotearoa New Zealand is denying natural justice to survivors by keeping some of its redress process secret.
The Survivors Network of those Abused by Priests (SNAP) said majority of complaints were not upheld and that a committee set up to assess them, was held in secret.
Spokesperson Christopher Longhurst said when survivors ask why, the committee does not respond.
Longhurst said the person has the right to know why the complaint was denied and by who, otherwise it is a breach of natural justice.
''The ultimate person who denies it, is the Church authority which is the bishop or congregational leader, but then they go back to the secret committee, which recommends to them why it shouldn't be upheld.
''This is in a system that has a leader, Pope Francis in Rome, who has publicly asked bishops across the world to be open and transparent with survivors regarding their complaints.
''Here in New Zealand we have a process that is top secret,'' Longhurst said.
Catholic Church director for the National Office for Professional Standards Virginia Noonan said the names of the Complaints Assessment Committee are not currently published.
"The National Office for Professional Standards appoints independent external professionals to inquire into complaints of abuse. The Complaints Assessment Committee reviews the evidence gathered in that process. The final decision on whether to uphold a complaint is made by the relevant Church authority, either a bishop or a congregational leader.''
She said many complaints are upheld.
Noonan said the Catholic Church and the National Office for Professional Standards regularly review the relevant protocols and practices.
''The views of survivors and their advocates are actively sought in these reviews.''
RNZ asked the Catholic Church for details on the number of complaints received and how many were upheld.
Noonan said, ''Analysis of this information has not been made public previously, however this is a matter which the National Safeguarding & Professional Standards Committee will be considering in the future.''
SNAP said it has filed a complaint with Police.
It said the statement was against persons perpetrating mental and psychological harm on victims and survivors of clergy and religious child sexual abuse by their denial of natural justice through a top-secret redress process which SNAP now believes to be criminal.
SNAP said a number New Zealand Catholic Bishops and a member of the New Zealand Catholic Congregational Leaders Conference have been named in the statement.