M.S.S. v. BELGIUM AND GREECE JUDGMENT 59 of Article 13 is thus to require the provision of a domestic remedy to deal with the substance of an “arguable complaint” under the Convention and to grant appropriate relief. The scope of the Contracting States’ obligations under Article 13 varies depending on the nature of the applicant’s complaint; however, the remedy required by Article 13 must be “effective” in practice as well as in law (ibid., § 157). 289. The “effectiveness” of a “remedy” within the meaning of Article 13 does not depend on the certainty of a favourable outcome for the applicant. Nor does the “authority” referred to in that provision necessarily have to be a judicial authority; but if it is not, its powers and the guarantees which it affords are relevant in determining whether the remedy before it is effective. Also, even if a single remedy does not by itself entirely satisfy the requirements of Article 13, the aggregate of remedies provided for under domestic law may do so (see Gebremedhin [Gaberamadhien] v. France, no. 25389/05, § 53, ECHR 2007-II). 290. In order to be effective, the remedy required by Article 13 must be available in practice as well as in law, in particular in the sense that its exercise must not be unjustifiably hindered by the acts or omissions of the authorities of the respondent State (see Çakıcı v. Turkey [GC], no. 23657/94, § 112, ECHR 1999-IV). 291. Article 13 requires the provision of a domestic remedy allowing the competent national authority both to deal with the substance of the relevant Convention complaint and to grant appropriate relief, although Contracting States are afforded some discretion as to the manner in which they conform to their obligations under this provision (see Jabari v. Turkey, no. 40035/98, § 48, ECHR 2000-VIII). 292. Particular attention should be paid to the speediness of the remedial action itself, it not being excluded that the adequate nature of the remedy can be undermined by its excessive duration (see Doran v. Ireland, no. 50389/99, § 57, ECHR 2003-X). 293. Lastly, in view of the importance which the Court attaches to Article 3 of the Convention and the irreversible nature of the damage which may result if the risk of torture or ill-treatment materialises, the effectiveness of a remedy within the meaning of Article 13 imperatively requires close scrutiny by a national authority (see Shamayev and Others v. Georgia and Russia, no. 36378/02, § 448, ECHR 2005-III), independent and rigorous scrutiny of any claim that there exist substantial grounds for fearing a real risk of treatment contrary to Article 3 (see Jabari, cited above, § 50), as well as a particularly prompt response (see Batı and Others v. Turkey, nos. 33097/96 and 57834/00, § 136, ECHR 2004-IV); it also requires that the person concerned should have access to a remedy with automatic suspensive effect (see Čonka v. Belgium, no. 51564/99, §§ 81-83, ECHR 2002-I, and Gebremedhin [Gaberamadhien], cited above, § 66).