8 KIM v. RUSSIA JUDGMENT 41. The Court reiterates that the purpose of Article 5 § 4 is to guarantee to persons who are arrested and detained the right to judicial supervision of the lawfulness of the measure to which they are thereby subjected. A remedy must be made available during a person’s detention to allow that person to obtain speedy judicial review of its lawfulness. That review should be capable of leading, where appropriate, to release. The existence of the remedy required by Article 5 § 4 must be sufficiently certain, not only in theory but also in practice, failing which it will lack the accessibility and effectiveness required for the purposes of that provision (see Muminov, cited above, § 113, and Ismoilov and Others v. Russia, no. 2947/06, § 145, 24 April 2008, with further references). 42. The Court notes at the outset that a judicial review of the kind required under Article 5 § 4 cannot be said to be incorporated in the initial detention order of 19 July 2011. The thrust of the applicant’s complaint under Article 5 § 4 was not directed against the initial decision on his placement in custody but rather against his inability to obtain a judicial review of his detention after a certain lapse of time. Given that the applicant spent more than two years in custody, new issues affecting the lawfulness of the detention might have arisen in the meantime. In particular, the applicant sought to argue before the courts that his detention had ceased to be lawful after it had transpired that it was impossible to expel him to Uzbekistan. By virtue of Article 5 § 4 the applicant was entitled to apply to a “court” having jurisdiction to decide “speedily” whether or not his deprivation of liberty had become “unlawful” in the light of new factors which emerged subsequently to the decision on his initial placement in custody (see Azimov, cited above, §§ 151-152, with further references). 43. The Court observes that no automatic periodic extension of the applicant’s detention or any judicial review thereof took place during the entire two-year period that he remained in custody. The applicant’s attempts to seek any form of review were likewise unfruitful: two District Courts and the St Petersburg City Court refused to deal with the substance of his complaint about unlawful detention, finding that there was no need to vary the custodial measure or to review its lawfulness in the light of the new circumstances. The Court lastly notes that in the Azimov case, which featured a similar complaint, the Government did not point to any domestic legal provision which could have allowed the applicant to bring proceedings for judicial review of his detention pending expulsion (see Azimov, cited above, § 153); in the instant case, the Government also acknowledged a violation of Article 5 § 4. 44. It follows that throughout the term of the applicant’s detention pending expulsion he did not have at his disposal any procedure for a judicial review of its lawfulness. 45. There has therefore been a violation of Article 5 § 4.