Obligations · Rights · Options · Discussion 10
What can a court actually do?
Winning the legal proposition is only half the analysis. Before bringing a case, ask what order the court has power to make, whether that order fixes the practical problem, and whether another procedure offers a more direct remedy.
Habeas corpus: test the legality of detention
NZBORA s 23 expressly recognises the right of an arrested or detained person to have the validity of detention determined without delay by way of habeas corpus and to be released if the detention is not lawful.
The Habeas Corpus Act 2001 is designed for urgency. Applications take priority and the inter partes hearing is ordinarily allocated no later than three working days after filing.
Under s 14, if the defendant fails to establish that the detention is lawful, the High Court must, subject to the Act’s provisions, issue the writ ordering release.
That is a powerful but narrow remedy.
It is not a general damages proceeding and it is not the appropriate procedure for every complaint about how an arrest occurred.
A declaration: establish the legal position
The Declaratory Judgments Act 1908 allows the High Court to make binding declarations of right even where consequential relief is not claimed.
The Judicial Review Procedure Act also includes declarations among the forms of relief available on review.
A declaration can matter where the legal position itself needs authoritative determination.
But a declaration is not automatically the same thing as:
returning seized property;
releasing a detained person;
paying compensation;
reinstating a licence;
quashing a conviction;
or compelling a particular merits outcome.
The requested order must fit the proceeding and jurisdiction.
Judicial review: several forms of relief
Section 16 of the Judicial Review Procedure Act gives the High Court power to grant relief corresponding to mandamus, prohibition and certiorari, as well as declarations and injunctions.
If a statutory decision is unauthorised or otherwise invalid, the Court may set it aside.
Section 17 separately allows the Court to direct the decision-maker to reconsider and determine the matter again, generally or on specified issues.
Set aside
The challenged decision is invalidated rather than left operative.
Reconsider
The matter returns to the lawful decision-maker to decide again in accordance with the court’s directions and reasons.
Prohibit / restrain
Public-law relief can prevent unlawful action or preserve the position, subject to statutory rules and the identity of the respondent.
Declare
The court can state the legal rights or invalidity even where another practical step may still be needed.
Reconsideration does not guarantee the opposite result
This is one of the most important practical distinctions.
A court may find that a decision was reached unlawfully because relevant material was ignored, natural justice was denied, the wrong test was applied or another public-law error occurred.
The remedy may be to send the matter back.
The lawful decision-maker can then reconsider using the correct process and, depending on the facts and law, may still reach the same substantive result.
A successful review can prove that the first decision was defective without guaranteeing that the second decision will favour the applicant.
Interim orders: preserve the position before it is too late
Section 15 permits interim orders before final determination where necessary to preserve the applicant’s position.
That can matter where implementation of the challenged power would create consequences that are difficult to undo before the full hearing.
The Act contains special wording where the Crown is respondent, so the exact form of interim relief requires careful legal analysis.
The court can also refuse relief
Judicial review remedies are not entirely mechanical.
Section 18 preserves judicial discretion to refuse relief on recognised grounds.
Section 19 also allows relief to be refused where the only established problem is a defect of form or technical irregularity and no substantial wrong or miscarriage of justice occurred.
So proving a technical breach does not always produce a substantive remedy.
Appeal and review are different
A statutory appeal may permit a court or tribunal to reconsider merits to the extent the legislation allows.
Judicial review focuses on legality of public power and process.
Habeas corpus focuses urgently on lawfulness of detention.
A declaration determines legal rights.
A criminal proceeding may have its own remedies and evidential rules.
A civil claim may seek compensation or other relief subject to its own cause of action and requirements.
Remedy matrix
Consider whether habeas corpus is the appropriate urgent procedure.
Consider judicial review and whether interim relief is available and necessary.
Judicial review may provide setting-aside relief where the legal requirements are established.
Section 17 permits a direction to reconsider.
A declaration may be appropriate, depending on the issue and jurisdiction.
Do not assume a complaint, declaration, habeas corpus application or ordinary judicial review automatically awards damages. Identify the legal basis for monetary relief separately.
Use the criminal appeal or other procedure provided by law rather than assuming public-law review is a substitute.
The practical test before litigation
Ask five questions.
What exactly was unlawful?
What evidence proves it?
Which court or tribunal has jurisdiction?
What remedy can that forum actually grant?
Will that remedy solve the real problem?
That final question prevents a common mistake: spending enormous effort proving a point that produces no useful change.
The strongest legal strategy starts with the remedy, then works backwards to the power, evidence and forum.
The series closes where it began
Discussion 01 asked: what power are you exercising?
The final discussion asks: what power does the court have to correct it?
Between those two questions sit the obligations, rights and options that determine whether public authority is merely asserted or lawfully exercised.
The method is consistent throughout:
identify the power;
identify its conditions;
preserve the evidence;
separate compliance from consent;
separate arrest from force;
separate complaint from remedy;
and choose the forum capable of giving the outcome the law permits.
Primary and official sources
New Zealand Bill of Rights Act 1990, ss 23 and 27 ↗
Habeas Corpus Act 2001 — urgency and determination of applications ↗
Judicial Review Procedure Act 2016, ss 15–19 ↗
Declaratory Judgments Act 1908 ↗
Court-remedy legislation checked 1 September 2026. This page describes the statutory tools at a general level and does not claim that any particular remedy is available on any particular facts.