SEC. 54. Fraudulent Claims. - The Ancestral Domains Of lice may, upon written request from the ICCs/lPs, review existing claims which have been fraudulently acquired by any person or community. Any claim found to be fraudulently acquired by, and issued to, any person or community may be cancelled by the NCIP after due notice and hearing of all parties concerned. SEC. 55. Communal Rights. - Subject to Section 56 hereof, areas within the ancestral domains, whether delineated or not, shall be presumed to be communally held: Provided, That communal rights under this Act shall not be construed as co-ownership as provided in Republic Act. No. 386, otherwise known as the New Civil Code. SEC. 56. Existing Property Rights Regimes. - Property rights within the ancestral domains already existing and/or vested upon effectivity of this Act, shall be recognized and respected. SEC. 57. Natural Resources within Ancestral Domains. - The ICCs/ IPs shall have priority rights in the harvesting, extraction, development or exploitation of any natural resources within the ancestral domains. A non-member of the ICCs/IPs concerned may be allowed to take part in the development and utilization of the natural resources for a period of not exceeding twenty-five (25) years renewable for not more than twenty-five (25) years: Provided, That a formal and written agreement is entered into with the ICCs/IPs concerned or that the community, pursuant to its own decision making process, has agreed to allow such operation: Provided, finally, That the NCIP may exercise visitorial powers and take appropriate action to safeguard the rights of the ICCs/IPs under the same contract. SEC. 58. Environmental Considerations. - Ancestral domains or portions thereof, which are found to be necessary for critical watersheds, mangroves, wildlife sanctuaries, wilderness, protected areas, forest cover, or reforestation as determined by appropriate agencies with the full participation of the ICCs/IPs concerned shall be maintained, managed and developed for such purposes. The ICCs/IPs concerned shall be given the responsibility to maintain, develop, protect and conserve such areas with the full and effective assistance of government agencies. Should the ICCs/IPs decide to transfer the responsibility over the areas, said decision must be made in writing. The consent of the ICCs/IPs should be arrived at in accordance with its customary laws without prejudice to the basic requirements of existing laws on free and prior informed consent: Provided, That the transfer shall be temporary and will ultimately revert to the ICCs/IPs in accordance with a program for technology transfer: Provided, further, That no ICCs/IPs shall be displaced or relocated for the purpose enumerated under this section without the written consent of the specific persons authorized to give consent. SEC. 59. Certification Precondition. - All departments and other governmental agencies shall henceforth be strictly enjoined from issuing, renewing, or granting any concession, license or lease, or entering into any production-sharing agreement, without prior certification from the NCIP that the area affected does not overlap with any ancestral domain. Such certification shall only be issued after a field-based investigation is conducted by the Ancestral Domains Office of the area concerned: Provided, That no certification shall be issued by the NCIP without the free and prior informed and written consent of ICCs/IPs concerned: Provided, further, That no department, government agency or government-owned or -controlled corporation may issue new concession, license, lease, or production sharing agreement while there is a pending application for a CADT: Provided, finally, That the ICCs/IPs shall have the 19