Evidence obtained through a violation of Article 3 of the Convention and used against the defendant in the proceedings may have been obtained from a third party other than the defendant. Undoubtedly, whether the use of unlawful evidence obtained from a third party in this manner, through a violation of Article 3, renders the proceedings unfair when used against the defendant, is an important issue that needs to be resolved. The ECtHR has not changed its strict approach that evidence obtained in violation of Article 3 cannot be used in proceedings in such cases. For the ECtHR, in particular, has decided that the use of evidence obtained from a third party through torture in proceedings would amount to “a manifest denial of justice” or “a refusal/denial of justice” . As can be seen, this acceptance by the ECtHR is valid not only in cases where the victim of treatment contrary to Article 3 is the main defendant, but also when third parties are involved. (El Haski/Belgium, 2012, pr.85; Othman (Abu Qatada)/United Kingdom, 2012, pr.263 and 267; Kaçiu and Kotorri /Albania, 2013, pr.128) For example, if documentary or testimonial evidence obtained from a witness other than the defendant, or from another co-defendant, through torture or inhuman treatment is used against the defendant, the right to a fair trial will have been violated.