The applicants were accused of armed robbery. Several police officers were asked as witnesses, but their names were not disclosed and they were not invited to public hearings. Their statements were given only in front of the investigative judge.
The applicants complained that their conviction had been based essentially on the evidence of police officers whose identity was not disclosed to them and who were not heard either in public or in their presence in violation of their right to fair trial.
The Court stated that all the evidence must normally be produced at a public hearing, in the presence of the accused, with a view to adversarial argument. There are exceptions to this principle, but the defendant always must be given an adequate and proper opportunity to challenge and question a witness against him, either when he makes his statements or at a later stage.
The Court found that the use of statements made by anonymous witnesses can be used in some occasions, but the difficulties for the defence in those cases must be sufficiently counterbalanced by the procedures followed by the judicial authorities. A conviction should not be based either solely or to a decisive extent on anonymous statements. Any measures restricting the rights of the defence should be strictly necessary - if a less restrictive measure can suffice then that measure should be applied. The Court noted that in the particular case the applicants were not able to question the witnesses, the procedure did not allow the applicants verify whether the anonymous witnesses actually testified before the investigative judge and there were no well-grounded reasons why the witnesses had to stay anonymous.
The defence was not only unaware of the identity of the police witnesses but was also prevented from observing their demeanour under direct questioning, and thus from testing their reliability. Furthermore, the statements of the witnesses had been decisive in the applicants’ conviction. Therefore the Court ruled that the proceedings had been unfair in violation of the right to fair trial of the applicants.