(Series Information) European Papers - A Journal on Law and Integration, 2021 6(1), 357-389 | Article | (Table of Contents) I. A hybrid judicial actor entering the battlefield against EU fraud. - II. Brief overview of the EPPO's relevant features. - III. The Belgian system of judicial inquiries. - IV. Is a judicial inquiry compatible with the EPPO Regulation? - IV.1. No unambiguous prohibition of judicial inquiries. - IV.2. Interpretation confirmed by the drafting history of the EPPO Regulation. - V. Step-by-step analysis of a judicial inquiry in EPPO cases in Belgium: need for legislative amendments? - V.1. The opening of the EPPO investigation. - V.2. The conduct of the EPPO investigation. - V.3. The reallocation of an EPPO case from one Member State to another. - V.4. The closing of the EPPO investigation. - V.5. The reopening of a closed EPPO case. - VI. The Belgian EPPO Act: preserving the status quo. - VI.1. Brief overview of the Belgian EPPO Act. - VI.2. Is the new Belgian legislation in conformity with the EPPO Regulation? - VII. Conclusion. | (Abstract) The European Public Prosecutor's Office (hereafter EPPO) was established by way of enhanced cooperation, with the adoption of Council Regulation (EU) 2017/1939 (hereafter EPPO Regulation). It has the power to conduct criminal investigations and to directly act as the prosecuting authority before national criminal courts, which is revolutionary. Interestingly, the EPPO Regulation does not explicitly regulate the relation between the EPPO and national judges at the pre-trial stage, who may intervene punctually or, in some cases, even conduct the investigation. Indeed, some civil law systems have a system of shared investigation powers between the public prosecutor and the investigating judge, meaning that the latter conducts a judicial inquiry, while the former is responsible for the prosecution. This raises the delicate question whether a judicial inquiry is compatible with the EPPO Regulation. This Article analyses this question, which hugely impacts the ...