Introduction. The present work is devoted to analysis of development of legislative framework of participation of private security organisations in the Russian Federation in activities on protection of rights and freedoms of persons and legal entities, protection of society and state. For these purposes, the regulations of the Law of the Russian Federation of March 11, 1992 2487-I “On private detective and security activities in the Russian Federation” are addressed and entering into force as from 1 September 2026. Federal Law of November 30, 2024. 427-F “On private security activities” (further – Federal Law 427-F) in the context of the relationship between the powers of private security organisations and public law enforcement agencies. Methods. The author uses a set of methods developed and tested by constitutionallegal science. Methods of analysis and synthesis, induction and deduction, dialectical approach were actively applied; special attention was paid to the method of comparative jurisprudence. Results. The study examines forms and methods of involving private security organisations in law enforcement activities used in other countries. Based on an analysis of the regulations of Russian legislation and foreign experience, it is noted that since the entry into force of the Federal Law 427-F begins a new stage in the institutional development of private security activities. The work also formulates proposals for further improvement of the regulatory legal enforcement of private security activities.