On 8 June 2017, the ECtHR delivered its ruling in case M.M. v. Bulgaria, which concerned the detention and attempts to remove a stateless man of Palestinian origin to Syria. By this judgement, the Court confirmed its view on that detention must not be used arbitrarily and that it is necessary to provide lawful review of detention as soon as possible.

The applicant arrived in Bulgaria in 2008 and had his asylum application and subsequent appeals rejected. In 2012, he was granted humanitarian status, with a residence permit valid until April 2015. However, the Bulgarian National Security Agency ordered the withdrawal of his residence permit and his expulsion from the territory, together with a ten-year entry ban. It was found that the applicant was considered a threat to national security due to Skype conversations with a person in Syria. He was expelled to Lebanon but was refused entry and returned back to Bulgaria, where he was arrested due to the entry ban. He was in detention from December 2013 to December 2014, after a lengthy judicial procedure. The Administrative Tribunal ordered his release based on the fact that the expulsion order could not be executed and that the risks to national security were solely based on affirmations by the National Security Agency without elements of proof. He was once again granted protection on humanitarian grounds with a renewed residence permit.

ECtHR found that the duration of the appeal proceedings to contest his detention was excessive and failed to respect the guarantees under Article 5. The ECtHR found that the 42-days delay by the Supreme Administrative Court to give a first ruling on the case was excessive, particularly taking into account that the detention had been ordered by a non-judicial body and that it was the first examination of the lawfulness of the detention. Furthermore, the Supreme Administrative Court did not rule on the facts of the appeal, but only referred the case back to the lower Administrative Tribunal, thus delaying a final decision for almost three months. Therefore, the ECtHR found a violation of Article 5 § 4 ECHR.