<![CDATA[The regulation regarding the inheritance rights of illegitimate children from biological fathers still raises legal issues due to the disharmony between Law Number 1 of 1974 concerning Marriage, Constitutional Court Decision Number 46/PUU-VIII/2010, and the Compilation of Islamic Law. These differences in regulations create legal uncertainty regarding the position of illegitimate children in obtaining inheritance rights from their biological fathers. This study aims to analyze the regulation of inheritance rights of illegitimate children from biological fathers based on the provisions of Indonesian positive law and examine the harmonization of these regulations from the perspective of the Marriage Law and the Compilation of Islamic Law. This study is a normative legal research using a statutory approach, a conceptual approach, and a case approach. Legal materials are analyzed qualitatively through literature studies. The results of the study indicate that Constitutional Court Decision Number 46/PUU-VIII/2010 has expanded the civil relationship of illegitimate children with their biological fathers as long as it can be proven based on science and technology or other evidence according to law. However, the implementation of inheritance rights still faces obstacles due to the lack of harmony in the Compilation of Islamic Law. Therefore, regulatory harmonization is needed to ensure legal certainty, justice, and legal protection for the civil rights of illegitimate children.]]>
