In Ukraine, starting from February 2022, every day servicemen of the Russian army commit crimes that are a direct violation of international humanitarian law, not only on the front line, but also in the depths of the country, in the central and western regions. The author of the article analyzes the procedure for pre-trial investigation of international criminal crimes and the role of non-governmental public human rights organizations in this process. In addition, the new functions assigned to NGOs as separate non-governmental human rights organizations that have been operating on the territory of Ukraine since the beginning of the full-scale invasion were considered. The legal mechanisms for the involvement of NGOs in the collection of evidence on the ground, as well as the possibility of taking into account the collected information by international justice bodies, were studied. Specific examples and initiatives of the public sector, within the scope of the issue being studied, are given, and the functions, competences, and opportunities for increasing the effectiveness of NGO activity in the conditions of war are defined.
 It was concluded that non-governmental organizations, including human rights organizations, during the war in Ukraine discovered new areas of work and expanded the possibility of cooperation with state bodies. In turn, law enforcement agencies have provided access to limited information for the NGOs themselves by internal orders, which together increases the effectiveness of the pre-trial investigation of committed crimes. Thanks to this, feedback has been established. Special attention should be paid to the work of foreign NGOs and volunteers, which contributes to the recording of war crimes and crimes against humanity, which current Ukrainian refugees witnessed or became victims of.
 It was concluded that the main areas of evidence-gathering NGO activity are the following: 1) dissemination of information in the mass media about the condition of refugees who suffered as a result of the crimes of the Russian military, documenting the stories of witnesses of such offenses. In particular, the facts of torture and sexual violence (from the testimonies of refugees from Ukraine) were reported by the mass media in many European countries and beyond; 2) provision of advisory assistance regarding high-quality recording of episodes of criminal acts in order to recognize such evidence as appropriate; 3) peaceful gatherings and protests of public organizations, the active public against Russia’s war crimes in Ukraine, which, of course, is of great importance for the international community to recognize their severity and massiveness.
 It was concluded that the wide international recognition of the war crimes of the Russian Federation creates opportunities for the successful initiation of the International Tribunal or other judicial formats (such as the International Criminal Court, the Extraordinary Chamber) to bring the perpetrators to justice. All international actors collect evidence according to the clear requirements and standards of the International Criminal Court, and subsequently either transfer it to it or accumulate it in the prosecutor’s offices of certain countries for further referral to a designated responsible judicial body.