If the ECJ accepts that the principle of prohibition of fraud and abuse of rights is a general principle of EU law allowing the national courts to refrain from applying the E 101 certificate fraudulently obtained or invoked, the Court also readily specifies that such principle can only apply in very specific circumstances. The judge of the host Member State must have found that the certificates were obtained fraudulently; this entails that the authority of the host Member State has reported the proof of the fraud (objective and subjective elements). The subjective element (fraudulent intent) will be difficult to report in most cases. For this reason the use of the dialogue and conciliation procedure is central, since the institution which issued the E 101 certificate should, as a general rule, be regarded as being best placed to assess the factual elements.
Morsa, M. (2018). judgment-altun-priority-to-fight-against-cross-border-social-security-fraud-and-social-dumping-or-a-just-a-trick-mirror. UNIO - EU Law Journal, Volume(6), 2. https://hdl.handle.net/2078.5/54998 (Original work published 2018)