OLAF is a vital player in the approach to fighting fraud directed against the EU’s financial interests. Its institutional structure is a hybrid one. The Office plays an important role in the EU’s general anti-fraud policy, but also needs strong operational independence. Our analysis presents a complicated picture. Many actors are involved in OLAF’s political and judicial accountability. The relationships between these actors are not always clear. This can not only lead to duplications, but also to gaps in accountability. These gaps manifest themselves at the interface of the EU and national levels, as well as in the division of labour between the fora for political and judicial accountability. The authors submit that clearer rules are needed for the cooperation with national authorities, the admissibility of OLAF evidence in national proceedings and a body which can address complaints in a truly independent manner.