According to the CJEU press release:

On 12 December 2019, a vessel carrying 45 men from third countries, including VL, a Malian national, was intercepted by the Spanish Marine Rescue service off the coast of Gran Canaria (Spain), where the third-country nationals were taken. The following day, an administrative authority ordered their removal and made a request for detention before the Juzgado de Instrucción nº 3 de San Bartolomé de Tirajana (Court of Preliminary Investigation No 3 of San Bartolomé de Tirajana, Spain). Once that court had informed him of his rights, VL stated his intention to apply for international protection. On account of the lack of available accommodation in a humanitarian reception centre, that court ordered that VL be detained in a detention centre for foreign nationals, where his application for international protection was to be processed. VL then appealed against the detention decision before that court, on the ground that it was incompatible with the Asylum Procedures Directive and Directive 2013/332 (‘the Reception Conditions Directive’). In those appeal proceedings, the court made a reference to the Court of Justice for a preliminary ruling, inter alia, on whether it fell within the concept of ‘other authorities’, within the meaning of the second subparagraph of Article 6(1) of the Asylum Procedures Directive, and, accordingly, whether it is likely to receive applications for international protection. It also asked the Court to rule on the lawfulness of holding VL in detention. 

The Court held that examining magistrates called upon to adjudicate on the detention of a third-country national without a legal right of residence fall within the concept of ‘other authorities’, within the meaning of the second subparagraph of Article 6(1) of Directive 2013/321 (‘the Asylum Procedures Directive’), which are likely to receive applications for international protection, even though they are not competent, under national law, to register such applications. On that basis, examining magistrates are required to inform the applicant as to the specific procedures for lodging such an application. The Court also ruled that the fact that it is not possible to find accommodation in a humanitarian reception centre cannot justify holding an applicant for international protection in detention.