The Petitioners brought this suit as citizens and taxpayers, assailing the constitutionality of certain provisions of the Indigenous Peoples Rights Act of 1997 (IPRA). They complained, among others, that the provisions amounted to an unlawful deprivation of the State’s ownership over lands of the public domain as well as minerals and other natural resources therein, and that they granted ownership over these natural resources to indigenous peoples. Thus they were unconstitutional. The provisions provided, inter alia, that ancestral domains including inalienable public lands, bodies of water, mineral and other resources found within ancestral domains were private but community property of the indigenous peoples and gave the indigenous peoples the responsibility to maintain, develop, protect and conserve the ancestral domains and portions thereof which were found to be necessary for critical watersheds, mangroves, wildlife sanctuaries, wilderness, protected areas, forest cover or reforestation. The petitioners also contended that, by providing for an all encompassing definition of “ancestral lands” which might even include private lands found within said areas, the provisions violated the rights of private landowners. In addition, the petitioners questioned the provisions of the IPRA making customary law applicable to the settlement of disputes involving ancestral domains and ancestral lands. They also prayed for the issuance of a writ of mandamus commanding the Secretary of Environment and Natural Resources to comply with his duty to control and supervise the exploration, development, utilization and conservation of Philippine natural resources. After deliberating on the petition, seven judges of the Supreme Court voted to dismiss the petition, sustaining the validity of the challenged provisions or a part of them. Seven other members of the Court voted to grant the petition. As the votes were equally divided and the necessary majority was not obtained, the case was redeliberated upon. However, after redeliberation, the voting remained the same. Therefore, the petition was dismissed. In a separate opinion, judge Puno analyzed the development of the Regalian Doctrine in the Philippine Legal System, and argued that the provisions of the IPRA did not contravene the constitution, as ancestral domains and ancestral lands were the private property of indigenous peoples and did not constitute part of the land of the public domain.