competent have been made as a result of torture.18 By doing so, the Committee has set up a positive obligation upon States to examine whether evidence brought before them could be tainted by torture. This positive duty of the State mitigates the general rules on the burden of proof, which would normally require the complainant to prove his/her claim before the Committee, and produces what is normally referred to as a ‘shift of the burden of proof’. To trigger such procedure and thus the positive duty of the State, the complainant needs to allege prima facie evidence of the torture allegation, so as to demonstrate that his/her allegation are well-founded. Once the complainant has brought an arguable claim before the Committee, the fact that the State party does not refute the allegations nor include any specific information on the applicant’s claim in its observations to the Committee may be enough for the Committee to find a breach of Article 15. Similarly, the ECtHR has found that a prima facie allegation from the applicant suffice to trigger the procedure and shift the burden of proof to the State. It further clarified that even when it is not possible to establish a substantive violation of Article 3 ECHR based on the evidence brought before it, a procedural violation of Article 3 as well as a violation of Article 6 may nevertheless be found if the national courts in the criminal proceedings have failed to duly examine the applicant’s argument concerning the unlawfulness of the evidence .19 As mentioned by Judge Yudkivska in his concurring opinion: “The present judgment is a clear indication to the domestic courts that they must suppress not only evidence which is established to have been obtained as a result of ill-treatment, but must also discount any evidence where such treatment is prima facie alleged but cannot be proved on account of the police’s reluctance to conduct an effective investigation in this respect. Otherwise the admission of evidence – where there are unresolved doubts that it may have been obtained in breach of the most fundamental value of the Convention – undermines the integrity of the justice system and public confidence in it.” Yet, there are no reliable data on whether States parties are implementing these principles in practice and there seems to be generally little knowledge on how these standards should operate in the national systems (see also Notabene “The inadmissibility of torture tainted by torture: the case of Tajikistan”).20 Moreover, proving that evidence was obtained by ill-treatment may be even more difficult in transnational proceedings. In the 2011 case Ktiti v Morocco, the CAT Committee clarified that the Moroccan authorities had to ”verify the content of the author’s allegations” that the evidence at the basis of the extradition procedure was obtained by torture in Algeria and by not doing so it violated Article 15. In this case, the applicant referred inter alia to the Committee’s most recent concluding observations to substantiate its prima facie claim. 18 CAT Committee, PE v France, No 193/2001, CAT/C/29/D/193/2001, 21 November 2002, § 10. Fort further details see Giuliana Monina, ‘Article 15: Non-Admissibility of Evidence Obtained by Torture’ in Nowak, Birk, Monina, The United Nations Convention Against Torture and Its Optional Protocol: A Commentary (2nd edition 2019 OUP). 19 ECtHR, Bokhonko v. Georgia, App no. 6739/11 (22 October 2020) § 72-79 (on the procedural violation of Article 3 ECHR) and § 91 and 99 (on Article 6 ECHR). 20 E.g. in Poland the CAT Committee noted with concern that statistical data concerning cases in which charges have been dismissed on account of admission of evidence or testimonies obtained under torture or improper treatment are not collected, and recommended to provide it to the Committee in the next periodic report. See CAT Committee, Concluding Observations: Poland (29 August 2019) CAT/C/POL/CO/7, § 12 (f). 10