Purpose: The article examines the problem of ensuring objectivity and impartiality of criminal prosecution against individuals who generate an institutional conflict of interest, and identifies patterns in the development of legal mechanisms for overcoming such conflicts in domestic and international law. Methods: comparative legal method, formal legal analysis, historical legal method. Results: It is established that the institutional conflict of interest in the criminal prosecution of senior state officials is of a universal character, manifesting itself in both national and international jurisdictions. Comparative analysis reveals two fundamentally different models for addressing this conflict: the extra-systemic model (temporary special prosecutor — the United States, the Republic of Korea, Iceland) and the systemic model (permanent specialised prosecutorial divisions — Japan). International criminal law has developed the structurally analogous institution of the amicus curiae prosecutor. The parallel emergence of national and international mechanisms demonstrates an objective need of legal systems for devices capable of neutralising such conflicts. The practical effectiveness of any given model ultimately depends on the political culture of the society in question and the maturity of its democratic institutions. Discussion: The article offers a comparative legal analysis of national and international institutions of specialised prosecution, providing a basis for the development of hybrid models combining the advantages of extra-systemic and systemic approaches. The findings may be applied in the reform of legislation on prosecutorial activity and in the practice of international criminal tribunals.