Which of the following is NOT a main source of law in Australia?

International treaties are not considered a main source of law in Australia in the same way that statute law, common law, and constitutional law are. Statute law refers to laws made by Parliament, which are formal and written statutes that govern various aspects of society. Common law, on the other hand, arises from judicial decisions and precedents set by courts, providing interpretations that evolve over time. Constitutional law encompasses the body of laws that define the structure and powers of the government and the rights of individuals within Australia.

While international treaties can influence domestic law and may require implementation through statute or other means, they do not establish direct legal obligations on their own within the Australian legal framework unless they have been incorporated into domestic law through legislation. Thus, international treaties are not categorized as a main, standalone source of law in the same way the other sources are.