The case concerned the interpretation of Article 19 of the Directive (2011/95/EU, Qualification Directive). Specifically, the applicant had been granted subsidiary protection by the Austrian authorities on the mistaken basis that he was an Algerian national. The applicant was not responsible for the mistake, having rather declared throughout the proceedings that he was stateless. The CJEU held that under the Qualification Directive a State is under the obligation to revoke subsidiary protection if information emerges to prove that an individual never satisfied the requirements under the Directive.
An Austrian national by birth transferred his residence to Germany and naturalised as a German national. The naturalisation in Germany had the effect, in accordance with Austrian law, of causing him to lose his Austrian nationality. The German authorities later withdrew the naturalisation with retroactive effect, on the grounds that the applicant had not disclosed that he was the subject of a criminal investigation in Austria on account of suspected serious fraud, and that he had thus obtained German nationality by deception. The Court held that it is not contrary to EU law for a Member State to withdraw nationality obtained by deception, even if it results in losing EU citizenship, so long as the decision observes the principle of proportionality. Observance of the principle of proportionality requires the person concerned to be afforded a reasonable period of time in order to try to recover the nationality of their Member State of origin.