The object of research is public relations that arise, change and end during covert investigative (investigative) actions. Purpose: scientific substantiation in the system of NSDS of theoretical and legal bases of intervention in private communication, and also formulation of offers on optimization of legal maintenance of carrying out NSDS connected with intervention in private communication. Methods: general theoretical and special-scientific methods of cognition: dialectical, synergetic, formal-legal, comparative-legal, historical-legal, sociological methods (surveys, questionnaires), methods of analysis, synthesis, induction, deduction, analogy, abstraction and modeling, etc. Theoretical and practical results, scientific novelty: the author's definitions of basic terms in the field of interference in private communication in the interests of pre-trial investigation are formulated, namely: "interference in private communication", "principles of intervention in private communication", "means of intervention in private communication", that will allow to organize the conceptual and categorical apparatus, which forms the theoretical and legal basis of interference in private communication in the conduct of covert investigative (investigative) actions; it is substantiated that regulated by Art. 258 of the CPC of Ukraine interference in private communication in the system of covert investigative (search) actions is a generalized category, the essence of which is a set of actions of authorized entities aimed at secret access to the content of information transmitted from one person to another directly or by means of communication. any type and is stored under such physical or legal conditions under which the participants of the communication can count on the protection of information from the interference of others; the concept of the normative-legal act is offered, in which the order of the organization and carrying out of the types of interference in private communication defined by the legislation is defined and the following are provided: general provisions of interference in private communication; the procedure for organizing and conducting various types of interference in private communication; features of recording the course and results of interference in private communication. Practical significance: the provisions obtained as a result of the research conducted in the dissertation can be used: in the research field, for further research on the legal provision of rights, freedoms and legitimate interests of public law entities, development of proposals and recommendations, aimed at improving national legislation on the optimization of the legal basis for interference in private communication during covert investigative (search) actions; in the law-making sphere, during the development and improvement of the provisions of the CPC of Ukraine in order to specify the concept of NSDS, the grounds for their conduct, combining arrest, inspection and seizure into one NSDS and expanding the list of tools used during NSDS; in the field of law enforcement, as recommendations for resolving a number of problematic legal issues that arise during the pre-trial investigation of criminal offenses and the consideration of criminal cases in court; in the educational process, during the preparation of lectures, curricula, tests, textbooks and manuals, as well as during classes in the disciplines "Criminal Procedure", "Criminology", "Operational and investigative activities".
