See standing order 243. "The proceedings of a select committee or a subcommittee other than during the hearing of evidence are not open to the public and remain strictly confidential to the committee until it reports to the House." When the committee has reported back material can be released. If the committee is still considering an issue, it can not be.

Thank you for your advice on the standing orders, I'd believed the process to be a little more transparent. The following is what really concerns me about the process,

NEW ZEALAND HOUSE OF REPRESENTATIVES: NATURAL JUSTICE BEFORE SELECT COMMITTEES: EXTRACTS FROM THE GUIDE FOR WITNESSES
WHAT IS NATURAL JUSTICE?
Fairness: Put simply, natural justice is fairness of procedure. The Bill of Rights Act: The New Zealand Bill of Rights Act 1990 provides for every person to have the right to the observance of the principles of natural justice by a public authority. Select committees are expected to observe the principles. To ensure this, the Standing Orders adopted in 1995 (and amended in 1996) set out the natural justice procedures that committees must follow. Section 27(1) of the New Zealand Bill of Rights Act 1990.
  Natural justice before select committees: The principles of natural justice have been applied to select committee procedure by providing opportunities for people to respond to allegations made about them at a committee and for a fair process to be followed when evidence is given. Provision has also been made for the disqualification of a member for a particular item of business if that member has displayed clear bias against a person in respect of criminal activity under investigation by the committee.
  Parliament is an inherently political environment. While the procedures endeavour to make the processes fair, there is no intention to restrict members' participation in select committee processes merely because they have expressed a concluded view on an item of business. To do so would be to take the politics out of Parliament and to render its purpose meaningless. When considering the application of natural justice principles to Parliament, the political context in which they are to be applied must always be uppermost.
COMMITTEE POWERS TO CALL FOR EVIDENCE
  Persons, papers and records: Select committees have extensive powers to call for persons, papers and records (evidence). The powers are derived from the Legislature Act 1908, which gives effect in New Zealand law to parliamentary powers operating in the United Kingdom at the time the act was passed. SO 203, section 242 of the Legislature Act 1908.
  Most evidence is given willingly to committees without resorting to these powers. However, should you receive a request from a select committee to appear before a select committee or to produce a document, there is an assumption that you will comply with the request. Ultimately a summons may be served requiring your attendance or the production of the document. SO 204.
  Parliamentary sanctions: A committee may resolve to report to the House a failure to supply information or to appear following a summons. Such a report might seek the backing of the House, which may order the appearance of the witness or the production of the information. SO 204(5).
  Failure to supply information or to appear following a summons are examples of actions that could ultimately result in a finding of contempt of the House. A person in contempt of the House is liable to punishment by the House. SO 396(o) and (q).
GIVING EVIDENCE BEFORE A SELECT COMMITTEE
  Normal practice: Most evidence is heard in open session where the news media and other members of the public may be present and report on proceedings. There are provisions for hearings in private or secret and these are discussed in the section headed "Your rights as a witness". SO 219.
  Evidence is not normally transcribed and there is no official record of oral evidence unless a committee specifically resolves to have the evidence recorded. Members have generally preferred the informality of a hearing that is not recorded. SO 235(1).
  When giving evidence before a committee, you are expected to be respectful and to tell the truth. Deliberately attempting to mislead a committee and "misconducting oneself" are examples of actions that could ultimately result in a finding of contempt of the House. SO 396(b) and (l).
  Evidence on oath: A committee can require a witness to give evidence on oath. This is an infrequent procedure but if it is used, such witnesses are subject to the laws of perjury and face the possibility of criminal prosecution if there is evidence of perjury. SO 228, section 252 of the Legislature Act 1908, section 108 of the Crimes Act 1961.
  Transcripts of evidence: In the event of a committee deciding to record and transcribe your evidence, a transcript will be made and you will be given reasonable opportunity to correct any errors of transcription. SO 235(2).
  Transcripts become publicly available when the committee reports to the House and they may form part of the report. They could also be released earlier if the committee decides to do so. Until they are released and become a matter for public record, transcripts remain confidential to the committee and you are not able to release them yourself.
  Freedom of Speech in Parliament: Article 9 of the Bill of Rights 1688 provides as follows:
That the freedom of speech, and debates or proceedings in Parliament ought not to be impeached or questioned in any court or place out of Parliament.
  This provision is in force in New Zealand law by reason of the Imperial Laws Application Act 1988 and it forms the basis of freedom of speech in Parliament. It ensures that witnesses have absolute privilege when giving evidence in parliamentary proceedings and cannot be liable in defamation for their comments to a committee. It does not protect witnesses if they repeat their comments outside a committee meeting. Section 3 of the Imperial Laws Application Act 1988, section 13(1) of the Defamation Act 1992.
  The natural justice procedures described in this booklet ensure that, in the absence of recourse in the courts, if serious allegations are made about you that may seriously damage your reputation, you have the opportunity to put your side of the case.
  Criminal wrongdoing: When giving evidence, you should be particularly careful about making allegations of criminal wrongdoing. A committee cannot investigate specific allegations of crime on the part of named individuals unless it has authority to do so from the House. While there is nothing to stop committees looking generally into the nature of criminal activity, the committee might not allow specific allegations to be made. SO 206
  Charges against Members of Parliament: Select committees cannot inquire into the private conduct of Members of Parliament. If you make allegations that reflect on the private conduct of Members of Parliament while giving evidence, the committee will not proceed further on the allegations apart from informing the Member and giving that Member the opportunity to make a statement. Unless the House determines otherwise, the Privileges Committee is the only committee that can investigate the conduct of Members of Parliament. SO 207
  Matters before the courts: When giving evidence before a select committee, you should take care not to comment upon matters that are before a court of record (Judicial Committee of the Privy Council, Court of Appeal, High Court, Courts Martial Appeal Court, Employment Court, Maori Appellate Court, Maori Land Court, District Courts (which includes the Family Courts and Youth Courts) and Environment Court) (sub judice). This is prohibited when there is danger of prejudice to a fair trial. The chairperson may, therefore, rule such references out of order. Avoiding comment on matters before a court is an important principle of our constitutional system and it is one respected by Parliament. However, the sub judice rule does not prevent the House and its committees from legislating. The fact that a matter is before a court does not stop Parliament passing legislation dealing with the matter. SO 115, 116
  If you are planning to make an allegation that may seriously damage a person's reputation you should be aware that the procedures set out in this booklet will be followed and that the process might have some impact on your own reputation, especially if you are unable to support your allegations with evidence.
  Matters of concern: If you have any matters of concern about giving evidence before a select committee, you are entitled to raise these with the clerk of the committee prior to giving evidence. Such concerns will be drawn to the attention of the committee. SO 224(1)
  If you need to consult the evidence you have supplied to a committee you can have reasonable access to that material. SO 238
YOUR RIGHTS AS A WITNESS
  Private and secret evidence: Evidence given in private is not open to the public or available to the media and remains confidential to the committee until it reports to the House. A decision by a committee to hear evidence in private must be unanimous. SO 220
  Evidence can also be given in secret and may not be disclosed by any party even after there has been a report to the House. A decision by a committee to hear evidence in secret must also be unanimous. SO 222
  You have the right to ask to be heard in private or secret. If you do ask to be heard in private or secret, you are required to give reasons for doing so. You can ask to be heard in private or secret at any time while you are appearing before the committee. SO 223(1) and (2)
  If a committee agrees to your request to be heard in private or secret you will be informed that private evidence becomes publicly available once the committee reports to the House or that secret evidence can be made available by order of the House. Any evidence you give in private may also be supplied to a person who is the subject of any allegations you make that may seriously damage that person's reputation. Evidence received in secret cannot be similarly released given that its permanent secrecy means that a person's reputation is not at risk. SO 223(3)
  Written submissions: If you are asked to give oral evidence before a committee, you will be informed of the opportunity to make a written submission prior to your appearance. You might find this useful as a permanent record of your position on the matter before the committee because oral evidence is generally not recorded. Written evidence gives you the opportunity of making a fully considered statement that may not be possible in oral evidence. SO 225
  Objections to answering a question: You can object to answering a question on the ground that it is not relevant to the item of business before the committee. If you do this the chairperson of the committee then determines whether the question is relevant. The chairperson will disallow a question that is determined to be irrelevant. SO 232(2)
  If you do not wish to answer a relevant question you may object to answering it and state your grounds for the objection. At this point, the question may be withdrawn or the committee may consider the matter in private to consider whether it requires an answer. At the same time the committee may consider whether the answer might be received as private or secret evidence. Once a committee informs you that it requires an answer you are expected to provide it. If you do not answer, the committee may report the matter to the House or your refusal could be raised as a matter of privilege. Refusal to answer is an example of an action that may be considered a contempt of the House. SO 233, 234, 396(q)
  Legal counsel: When you give evidence before a committee you may be accompanied by legal counsel of your choice and you may consult that person throughout the hearing. SO 230(1)
  Counsel may make written and oral submissions on the procedure to be followed by the committee, although an oral submission is subject to the committee's agreement. On your behalf, counsel may also object to questions on the same grounds as set out above. If there is risk of your reputation being seriously damaged by the committee's proceedings, counsel may ask the committee to hear further witnesses but the committee itself decides if it will do so. There is no provision for counsel to cross-examine witnesses. SO 230(2)
YOUR RIGHTS WHEN ALLEGATIONS HAVE BEEN MADE ABOUT YOU
  Allegations: The nature of Parliament is such that people often say hurtful things about other people. The House has not sought to impose procedures that limit freedom of speech in Parliament or that would compel committees to follow up every adverse comment. However, if an allegation is made about a person that may seriously damage his or her reputation, there are specific procedures that must be followed. "Person" is taken to include a body corporate.
  There may be occasions when allegations that may seriously damage a person's reputation and that are not directly relevant to the proceedings are made during a hearing. Under these circumstances, the committee can weigh up the value of the evidence against the risk of damage to reputation and may choose to return the evidence so that it does not form part of the proceedings. If the evidence is being transcribed, the allegations could be expunged from the transcript. Alternatively, the committee may seek an order of the House to withhold publication of the material. If these procedures are followed, right of reply may no longer be an issue because in most circumstances there will no longer be any risk of serious damage to reputation. SO 237
  Right of reply: If allegations have been made in select committee proceedings about you that may seriously damage your reputation, you will be informed of those allegations. You will then be given reasonable opportunity to respond by making a written submission and by appearing before the committee. Such a response will be received as evidence in the usual way. SO 226.
  If you consider that the evidence of additional witnesses is in your interest you may ask the committee to hear from these witnesses. However, the decision whether or not to hear these witnesses rests with the committee. SO 226(2)(b)
  Access to personal information: If allegations that may seriously damage your reputation have been made about you in select committee proceedings, you may request any material held by the committee that contains personal information about you. This includes otherwise confidential committee proceedings but not secret evidence. SO 239(1)
  A request for personal information will be considered by the committee and the material may be supplied to you if the committee agrees that your reputation is at risk of serious damage. The material may be supplied in a form different from that requested if this avoids undue difficulty, delay or expense. If any of the material has not been released publicly, its supply to you does not constitute public release and you are expected to respect the confidentiality of the material. The clerk of the committee can advise you on the status of the material provided. SO 239(2) and (3)
  If you are due to appear before a select committee as a witness, the committee will give you any material it has (other than secret evidence) that contains allegations that may seriously damage your reputation, regardless of whether or not you have requested it. As stated above, you will be expected to respect the confidentiality of any material that has not been released publicly. SO 224(2)
  Bias: If a member of Parliament has alleged that you have committed a crime or has expressed a concluded view on your involvement in any conduct or activity of a criminal nature, that member can be excluded from any related select committee proceedings. That member can also be excluded from participating in any other select committee meeting where serious damage to your reputation may occur. Such exclusion is on the grounds of "apparent bias" and ensures that the member is not being a judge in his or her own cause, one of the basic principles of natural justice. SO 217.
  An exlcusion for apparent bias does not occur automatically. You can make a complaint of apparent bias if you are the subject of the allegations or a member of Parliament may make such a complaint. The complaint must be in written form and addressed to the chairperson of the select committee. The chairperson will then decide whether or not the member will be excluded after seeking that member's comment. A committee member can appeal that decision to the Speaker, whose decision is final. SO 218.
  A pecuniary interest of a member of Parliament can also be a form of bias when it is directly relevant to the committee's proceedings. Members must declare such interests before participating in proceedings related to the item of business and can be found in contempt if they fail to do so. SO 168 to 170, 399.
YOUR RIGHTS IN RESPECT OF COMMITTEE FINDINGS
  Adverse findings: Select committees regularly make reports to the House on various items of business. Sometimes they make findings that could be described as "adverse". These could range from a criticism of a particular practice in a government department, a finding of gross incompetence, or even criminal negligence on the part of a named individual or group of people, the latter of which is rare.
  Submissions on adverse findings: Before a report is presented to the House, the committee must distinguish between an adverse finding that is a simple criticism and one that may seriously damage a person's reputation. In the latter case, if you are the subject of the finding, the committee must inform you of it and give you reasonable opportunity to make submissions on the findings. The committee must take those submissions into account before finally reporting to the House. If there is no risk of serious damage to reputation you are not likely to see the draft report or have the opportunity to make submissions on it. SO 245
  If a committee makes part of its draft report available to you for you to make a submission on a finding, it does so on a confidential basis. The contents of the report do not become publicly available until the committee reports to the House. Premature release of a select committee report is an example of an action that can result in a finding of contempt. SO 240, 396(m)