Nachtigall Battalion
Some sources contend that members of the Ukrainian auxiliaries from the Nachtigall Battalion were responsible for the murders. According to Canadian Institute of Ukrainian Studies, this claim originated with the Soviet sources and has been disputed. Memorial has published documents which claim to document the Nachtigall participation in those events as a KGB disinformation. Stanisław Bogaczewicz, of the Polish Institute of National Remembrance said that Nachtigall soldiers took part in the arrests, but not in the murders, and that their role in this event needs further investigation. Sociologist Tadeusz Piotrowski noted that while the Nachtigall role is disputed, they were present in the town during the events, their activities are not properly documented, and that at the very least they are guilty of the passive collaboration in this event, for not opposing the atrocities. According to a Lviv historian, Vasyl Rasevych, the claims that Ukrainians participated in the July 1941 massacre are untrue and that no archival evidence exists to support this contention.