The subject of the article is the ideas of the Russian foreign agents J. Balaszewicz and A. Stempkowski about the revolutionary democratic organization of the Polish emigration Republican Polish Center (RPC), which existed in 1867–1870. In historiography, this organization has been studied mainly from the point of view of its ideological features on the basis of sources created in the emigrant environment. The authors emphasize the expediency of a comprehensive treatment of alternative materials, Russian agent reports, that have been used only sporadically in the study of this topic. They allow us to shed light on the subjects that were previously on the periphery of the research optics, i.e. the problems of the involvement of the RPC in the counterfeiting of Russian banknotes and in plans to assassinate European monarchs. In the context of the problems under study, the question of the role of this organization in the international revolutionary movement is also raised in a new way. The authors examine two previously unused fragments of Stempkowski’s reports. The first of them contains data on the attitude of General J. Hauke-Bosak to counterfeiting, and the second one informs of the interception of the well-known letter of the Italian revolutionary G. Mazzini to the RPC, in which he expresses his opinion on the Slavic question in the Balkans and the role of the Polish national liberation movement in it. The article examines Balaszewicz’s reports, already published in Polish translation, from the perspective of the problems under study. It emphasizes that, according to agents’ reports, the RPC was actively involved in the plans of Italian and French republicans led by G. Mazzini to eliminate Napoleon III, but did not have the necessary resources and allies among other Polish emigrants to organize assassination attempts against Alexander II, who was a higher priority target for the Poles. The authors conclude that the RPC appears to be a minor link in the revolutionary projects of international radicals in the optics of Balaszewicz and Stempkowski’s reports.