The Principle of Trust and the Bank’s Responsibility in Restricting Access to the AMPB Coordinator’s Account

This study examines whether the blocking of the bank account of a customer affiliated with the Aliansi Masyarakat Pati Bersatu (AMPB) complied with Article 140 of Law No. 20 of 2025 concerning the Criminal Procedure Code (KUHAP), and whether it was consistent with the bank's obligations under the fiduciary relation principle. Using normative legal research with statutory, conceptual, and case approaches, the study analyzes primary and secondary legal materials through deductive-prescriptive reasoning. The findings show that an account block is lawful only if it is ordered by an authorized official with the permission of the head of the district court or, in urgent circumstances, followed by court approval within 2x24 hours. Both routes require a criminal offense under process and a relevant connection between the account and the case. Because no public information is available on these elements, the bank's compliance cannot be confirmed and its liability remains conditional. The study recommends that banks verify the formal completeness of every blocking request, notify customers in writing of the grounds for blocking, and that policymakers establish a clear objection mechanism.