With the entry into force of the Criminal Procedure Code of Bosnia and Herzegovina, the roles of the prosecutor and the court have been changed significantly compared to the earlier legislation, especially in the investigative procedure. According to the existing normative framework, the role of the court in the investigation is much more passive since at this stage of the procedure the court does not control the merits of conducting the investigation. The mixed accusatorial concept of investigation as the one existing in the criminal justice system of Bosnia and Herzegovina has led to certain restrictions on the rights of the defence in investigation. Investigation is an important stage in criminal proceedings that is conducted for evidence and data collecting necessary to decide whether to file an indictment or discontinue the proceedings, as well as for evidence that can be presented at the main hearing and upon which the judgment is rendered. It is therefore necessary to ensure that a proper and lawful investigation is conducted. This means to make sure that all parties involved in the investigation, especially defence are treated in a fair manner. The right to defence is a fundamental human and constitutional right guaranteed by international conventions. The right to defence results in several individual rights enjoyed by suspects in preliminary proceedings. In order to ensure effective judicial protection of the rights of the suspects, the paper analyses the domestic criminal justice system and presents comparative legal solutions regarding the protection of procedural rights of the defence in investigation. The fundamental issues in analysing regulatory framework in Bosnia and Herzegovina are the lack of effective judicial protection of procedural rights of the defence, the absence of an effective legal remedy to conduct an investigation facilitating the principle of a fair trial for defence and the principle of equality of arms in pre-trial proceedings. In addition, the paper analyses the issue of informing the suspect of an order for investigation, since according to applicable regulations, the suspect does not even need to know about an investigation conducted against him, which is a violation of the principle of right to a fair trial. [ABSTRACT FROM AUTHOR]