Country
Justice and public safety in New Zealand
New Zealand (Aotearoa) is a unitary common-law state with no single written constitution: Parliament is sovereign and the courts cannot strike down statutes. Its justice functions are all national, its prosecution follows a Law-Officer model rather than a Director of Public Prosecutions, and — in the common-law manner — the police investigate independently of both ministers and prosecutors. Tikanga Māori is a recognised source of its law.
Institutional facts on these pages were checked against their sources on . Where a cited provision carries a scheduled change, the page states the date.
New Zealand (Aotearoa) is a unitary parliamentary state with a common-law tradition and, unusually, no single supreme-law constitution. Its constitutional framework is uncodified — the Constitution Act 1986 together with convention, the common law, and the Treaty of Waitangi / Te Tiriti o Waitangi. The Constitution Act 1986 recognises the three branches of government, "each [operating] independently of the others" (the separation of powers), and protects judges' tenure and salary (sections 23 and 24).
Everything runs through national institutions: a unified court system topped by the Supreme Court, a single New Zealand Police force, the Crown's Law Officers and Crown Solicitors for prosecution, and the Department of Corrections. And tikanga Māori is a recognised source of the country's law — the Supreme Court has accepted it "was the first law of Aotearoa New Zealand".
Jurisdictions modelled
A territory can exist administratively without being a separate legal jurisdiction. This table records, for each modelled tier and territory, whether it has its own arrangement for a function, whether the function is organised nationally, or whether we have simply not researched it.
| Jurisdiction | Level | Courts | Prosecution | Policing |
|---|---|---|---|---|
| New Zealand | country | own | own | own |
unknown means not researched. It is never a synonym for none: an unresearched territory does not inherit the metropolitan arrangement.
What has not been researched
These areas have no page. That is a statement about our research, not about New Zealand: each of these institutions exists, and we have simply not established enough from primary sources to write about it responsibly.
- Forensic systemNot researched
- The organisation of forensic science in New Zealand (the Institute of Environmental Science and Research, which provides forensic services to the Police) has not been read to the standard required, and forensics is a safety-sensitive section where an under-sourced description is specifically forbidden.
- Border and customsNot researched
- Border and customs in New Zealand involve the New Zealand Customs Service and Immigration New Zealand, and could not be researched to the standard required here without risking an inaccurate description of a security-adjacent function.
- Institutional historyNot researched
- New Zealand's institutional history — the Treaty of Waitangi and its ongoing settlement process, the move from Privy Council appeals to a domestic Supreme Court, and the development of tikanga in the common law — cannot be written responsibly from general knowledge and requires scholarly and archival sources not consulted here.
- Institutional timelineNot researched
- A timeline requires each milestone to carry its own verified source and date. The dated facts established in this pilot — the Constitution Act 1986, the Policing Act 2008, the 2004 creation of the Supreme Court, and Ellis v R [2022] — are a start, but a responsible timeline needs primary sources for each milestone, which were not assembled here.
Sources
Sources
Constitution Act 1986 (New Zealand)
Parliament of New Zealand (via the UN FAO FAOLEX mirror) · Legislation · 1986-12-13 · link verified 2026-07-27
The Constitution Act 1986 (Public Act 1986 No 114), fetched as a PDF from the UN FAO FAOLEX mirror (the official legislation.govt.nz is behind an AWS WAF JavaScript challenge) and text-extracted; ss 23 and 24 re-confirmed verbatim in two passes. Supports that New Zealand has no single supreme-law constitution — the Act organises the State into Part 1 (the Sovereign), Part 2 (the Executive), Part 3 (the Legislature) and Part 4 (the Judiciary) — and s 23 (a High Court judge may be removed only by the Sovereign or Governor-General on an address of the House of Representatives, on the ground of misbehaviour or incapacity) and s 24 (a judge's salary may not be reduced during their commission). Establishes judicial independence and the uncodified, parliamentary-sovereignty framework.
Courts of New Zealand — the judiciary and the courts
Courts of New Zealand (Te Kōti o Aotearoa) · Government publication · link verified 2026-07-27
The judiciary's own site, read directly. Supports that "the Constitution Act 1986 recognises the three branches of government — the legislature (Parliament), the executive … and the judiciary", that "each operates independently of the others … known as 'the separation of powers'", and that the security of tenure and salary in ss 23 and 24 are described as "ancient guarantees"; and the ordinary court hierarchy (Supreme Court → Court of Appeal → High Court → District Court, plus specialist courts including the Māori Land Court).