Kernrechtsfrage
Whether the public-law appeal against the detention prolongation decision was admissible.
Extrahierter Entscheid
The appeal was admissible because the detention order was still in force, the filing was timely and properly reasoned, and the appellant had standing.
Extrahierte Begründung
In immigration coercive-measure cases, the ordinary remedy is a public-law appeal; the court examined jurisdiction and admissibility ex officio.