The contribution deals with the issue that is more and more resonant in the field of interrogation of witness in criminal proceedings not only at the level of legal theory but also at the level of application practice – it is the question of the need to respect the principle of contradictory within the realization of the abovementioned procedural act. In this context we are confronted with the requirement that the testimony of witnesses in criminal proceedings should have the so-called contradictory character which arises directly from Article 6 section 3 letter d of ECHR.