Sexual violence against children committed by biological parents constitutes a complex human rights violation, as it occurs within family power relations that are difficult to reach through external oversight. Indonesian regulation addresses this issue through three overlapping legal regimes, namely the Criminal Code, the Child Protection Law, and the Sexual Violence Crimes Law, yet prior studies have rarely examined how these three regimes should relate to one another, particularly through the principle of lex specialis derogat legi generali, when the perpetrator holds the status of biological father. This study aims to analyze the application of criminal provisions to a reported case of sexual intercourse committed by a father against his biological child that remains under legal process, and to formulate the appropriate hierarchy among the three regulations. This study employs normative legal research with a statute approach and a case approach, referring to a case reportedly occurring in the Banten region. The findings indicate that the reported conduct potentially fulfills the elements of criminal offenses under all three regulations at once, such that the Child Protection Law and the Sexual Violence Crimes Law should be prioritized as lex specialis over the Criminal Code. This study further finds that the completeness of victim protection norms on paper does not necessarily correspond with their implementation in practice, so that strengthening technical law enforcement guidelines and pursuing further harmonization among the regulations remain necessary to ensure effective child protection.