Objectives:
This article addresses the issue of obtaining information through operational-reconnaissance activities during the preliminary verification stage of criminal proceedings, with a particular focus on non-repeatable actions. Information gathered through such activities may serve as the basis for a request to a prosecutor, who may, in turn, petition a regional court to validate these actions, thereby allowing the information to be used in subsequent stages of criminal proceedings. Furthermore, the legality of these actions will be subject to judicial review at the time of judgment.

Methods:
On one hand, we are dealing with significant state interests and national security, while on the other, there are mandatory guarantees that protect citizens' privacy and the confidentiality of correspondence and communication, and which also establish consequences for the abuse of rights. The Code of Criminal Procedure does not explicitly address these matters - in particular, the issue of evidence that is indirectly obtained through unlawful means.

Results:
Experience shows that attempts have been made to legitimize information obtained illegally, by using it to generate indirect evidence, and to introduce such information into criminal proceedings. This practice has drawn sharp criticism, particularly regarding covert operations conducted during preliminary investigative inquiries, which remained entirely beyond any form of oversight.

Conclusions:
The issue presented is of great practical importance; the lack of statutory regulation gives rise to significant interpretive difficulties and inconsistencies in case law. This publication is devoted to addressing these very issues.