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Papua New Guinea Law

Country Information

The Independent State of Papua New Guinea comprises the eastern half of the large island of New Guinea and a number of smaller island provinces extending from the nearby Bismarck Archipelago east to Bougainville. There are 19 provinces in PNG, including the island of Bougainville and Port Moresby, the National Capital District. The diverse population embraces dozens of different ethnic groups. The current population (UN projection, mid-2019) is estimated at 8,526,000. The official languages are Tok Pisin (widely used and understood), English (spoken by 1%-2%) and Hiri Motu (spoken by less than 2%). There are about 839 indigenous spoken languages. Papua New Guinea is a member of the Commonwealth.

Colonial Background and Independence

The eastern half of the island of New Guinea was divided between Germany and Britain in 1885. The German colony was named ‘German New Guinea’. ‘Papua’ was firstly a British protectorate and then became a British colony in 1888. It was placed under the authority of the Commonwealth of Australia in 1902 and renamed the Territory of Papua. After World War I the British Government assumed a mandate from the League of Nations to govern on behalf of Australia. Japan occupied the island during World War II. After the surrender of the Japanese occupying forces at the end of the War, the United Nations granted the trusteeship of both territories to Australia, which continued to administer the combined areas of Papua and New Guinea until independence in 1975. Papua New Guinea finally achieved independence as a sovereign state in 1975.

For detailed country profile information about Papua New Guinea - its history, political system, statistics demographics, economics etc - refer to:

Doing Business in Papua New Guinea

World Bank - Doing Business in Papua New Guinea (open access)

The Country Review: Papua New Guinea (annual publication: 2000-current) (UniMelb access) provides a detailed and up to date overview of the economy and investment climate in PNG.


Popular daily PNG newspapers include:

The Pacific Islands Report is a news site developed and maintained by the Pacific Islands Development Program/East-West Center at the Center for Pacific Islands Studies of the University of Hawaii. It includes current Pacific Island information.

PNG Legal System & Sources of Law

Papua New Guinea has a mixed legal system of common law and customary law.

The sources of law are:

  • ‘Written law’ (the laws as stipulated in s 9 of the Constitution)
  • Common law (as stipulated in s 3(1) of the Underlying Law Act 2000).
  • Customary law (as stipulated in in s 3(1) of the Underlying Law Act 2000).

The sources of law are expressly listed in the Constitution and the Underlying Law Act 2000. The Constitution provides in s 9 that the laws of Papua New Guinea consist of only:

(a) the Constitution (the Constitution and Organic Laws are the supreme law – s 11)

(b) Organic Laws (defined in s 12 as laws made by Parliament that are ‘(a) for or in the respect of a matter provision for which by way of an Organic Law is authorized by this Constitution; and (b) not inconsistent with this Constitution; and (c) expressed to be an Organic Law’. An Organic Law may be altered only by another Organic Law, or by an alteration to the Constitution’. Organic laws are constitutional law ie: supreme laws.

(c) Acts of Parliament

(d) Emergency Regulations (see s 231)

(da) the provincial laws

(e) laws made under or adopted by or under this Constitution or any of those laws, including subordinate legislative enactments made under this Constitution or any of those laws

(f) the underlying law (see s 20)

The Underlying Law Act 2000 implements the mandate of section 20 of the Constitution to declare the ‘underlying law’. This is the non-codified sources of law in the PNG legal system, which are sources of law in addition to the legal rules found in the Constitution and legislation (the' written law' as contained in s 9 of the Constitution). The Underlying Law Act identifies in s 3(1) the main sources of the underlying law:

  • the customary law derived from the custom of the various peoples of New Guinea; and the
  • English common law (defined to include equity) in force immediately before 16 September 1975 (Independence Day and the day the Constitution entered into force), ‘notwithstanding their modification through an amendment, repeal or alteration by a statute of England unless the modifying statute has been adopted in Papua New Guinea’ (s 3(2)(b)).

For commentary on the Underlying Law Act and its implications, see:

Customary Law – the Constitution Schedule 1.2.2(1) and the Underlying Law Act s 1 both define custom as ‘customs and usages of the indigenous inhabitants of the country existing in relation to the matter in question at the time when and the place in relation to which the matter arises, regardless of whether or not the custom or usage has existed from time immemorial’. The Underlying Law Act gives precedence to the written law (s 4(2)(a), 4(3)(a) and s 6)) and precedence of customary law over the common law (s 4(3)(c) and s 6). Section 6 provides that courts shall apply the laws in the following order: (a) written law; (b) the underlying law; (c) the customary law; (d) the common law.

See also:

  • the Environment Act 2000, which defines ‘customary land’ in s 2 as ‘customary land within the meaning of the Land Act 1996’, and ‘customary rights to use of water or land’ as ‘rights to the use of water or land – (a) that are regulated by custom; and (b) that are being availed of at the time in question, or, in the normal course of land management, would be availed of in a customary manner within a reasonable period after that time’.
  • The Land Act 1996 s 2 defines:
    • ‘custom’ as ‘the customs and usages of indigenous inhabitants of the country existing in relation to land or the use of land at the time when and the place in relation to which the matter arises, regardless of whether or not the custom or usage has existed from time immemorial’;
    • ‘customary land’ as ‘land that is owned or possessed by an automatic citizen or community of automatic citizens by virtue of rights of a proprietary or possessory kind that belong to that citizen or community and arise from and are regulated by custom’;
    • ‘customary rights’ as ‘rights of a proprietary or possessory kind in relation to land that arise from and are regulated by custom’.
  • The Land Disputes Settlement Act 1975 s 39(2) provides that a Court must apply the customs of the area concerned, and in particular shall consider the customs of the area in so far as they relate to– (a) interests in land that are recognized by custom; and (b) the process by which such interests are allocated or re-allocated by custom. Section 39(3) provides examples of customary interests.

Online Guides to PNG Legal Research

PNG Legal Research Guide

Guide Author 

This Research Guide is created and maintained by the MLS Academic Research Service, Melbourne Law School.

Please contact us at with corrections, suggestions or comments about the Guide.