CCPR/C/118/D/2152/2012 the Optional Protocol, on the grounds that the author failed to exhaust the available domestic remedies in that he had failed to file an appeal before the Supreme Court of the Russian Federation. The Committee notes, however, that the State party does not specify the type of appeal available to the author. The Committee also notes that the State party has not challenged the author’s submission that the only remaining remedy for him would be to request a supervisory review. The Committee recalls its jurisprudence, according to which the filing of requests to a court for a supervisory review directed against court decisions that have entered into force and depend on the discretionary power of a judge constitutes an extraordinary remedy and that the State party must show that there is a reasonable prospect that such requests would provide an effective remedy in the circumstances of the case. 7 The State party has not shown, however, whether and in how many cases petitions to the president of the Supreme Court for supervisory review procedures were applied successfully in cases concerning degrading treatment of detainees by detention centre personnel. In those circumstances, the Committee considers that it is not precluded by articles 2 and 5 (2) (b) of the Optional Protocol from examining the present communication.8 11.6 The Committee takes note of the author’s claim that his rights under article 26 of the Covenant have been violated. However, in the absence of any other detailed and documented information, the Committee considers that the claim has been insufficiently substantiated for the purposes of admissibility and therefore considers it inadmissible under article 2 of the Optional Protocol. 11.7 The Committee notes the State party’s submission that the communication should be declared inadmissible as “insufficiently founded”. The Committee, however, considers that the author has sufficiently substantiated his claims under articles 7 and 10 (1) and (2) of the Covenant for the purposes of admissibility and proceeds with its consideration of the merits. Consideration of the merits 12.1 The Committee has considered the communication in the light of all the information made available to it by the parties, as provided under article 5 (1) of the Optional Protocol. 12.2 The Committee notes the author’s allegations that on 1 September 2006, after he had been transferred to detention centre No. 1, he was detained for 18 hours in a “rubber cell”, where there was a strong smell of rubber and an absence of ventilation; the cell was not heated, while the temperature outside was 12ºC; he was denied access to the toilet and not given food or water; and his sleep was disturbed every 30 minutes. The Committee, however, notes that the State party maintains that according to their records the author has never been placed in a rubber cell and that his allegation has been reviewed by the courts and found to lack credibility, while in his submission the author failed to indicate if and why these decisions were arbitrary or unreasonable. 12.3 The Committee further notes the author’s submission that he was kept in a punishment cell for a month and a half and that the said cell was 2m x 3m in size, located 7 8 10 See communications No. 836/1998, Gelazauskas v. Lithuania, Views adopted on 17 March 2003, para. 7.4; No. 1851/2008, Sekerko v. Belarus, Views adopted on 28 October 2013, para. 8.3; Nos. 1919-1920/2009, Protsko and Tolchin v. Belarus, Views adopted on 1 November 2013, para. 6.5; No. 1784/2008, Schumilin v. Belarus, Views adopted on 23 July 2012, para. 8.3; No. 1814/2008, P.L. v. Belarus, decision of inadmissibility adopted on 26 July 2011, para. 6.2; No. 2021/2010, E.Z. v. Kazakhstan, decision of inadmissibility adopted on 1 April 2015, para. 7.3; No. 1873/2009, Alekseev v. Russian Federation, Views adopted on 25 October 2013, para. 8.4; No. 2041/2011, Dorofeev v. Russian Federation, Views adopted on 11 July 2014, para. 9.6. See also communication No. 2141/2012, Kostenko v. Russian Federation, Views adopted on 23 October 2015, para 6.3.