In early August 1991—just a few weeks before the abortive coup that ultimately led to the Soviet Union’s collapse—a delegation of Chabad-Lubavitch rabbis arrived in Moscow, where they were told by the Ukrainian branch of the KGB that it wished to give them the arrest records of Rabbi Levi Yitzḥak Schneerson (1878-1944). Schneerson’s son, Menachem Mendel, was at the time of the visit the Lubavitcher rebbe; so the delegates traveled to Kiev to learn more. Dovid Margolin writes:
Levi Yitzḥak had been the high-profile chief rabbi of Dnepropetrovsk [now Dnipro], Ukraine, from before the 1917 October Revolution, when the city was still known as Ekaterinoslav, right up to the evening in April of 1939 when he was arrested by a KGB precursor, the NKVD. After ten months of brutal interrogations in secret-police prisons he was sentenced to five years of exile in the remote, mosquito- and disease-infested village of Chi’ili, Kazakhstan, where it was cold and damp in the winter and stiflingly hot in the summer.
[A] vice-chairman of Ukraine’s KGB . . . told the rabbis that Levi Yitzḥak’s arrest and subsequent treatment had been the sin of his predecessors, and thus not [his organization’s] own. Nevertheless, wishing somehow to rectify these past misdeeds by offering closure to the Jewish people, he [wanted to hand over] the arrest files.
Schneerson’s rabbinic career was largely defined by his resistance to the Bolsheviks’ repression of Judaism during the 1920 and 30s, recounts Margolin:
Following arrest and subsequent exile from the Soviet Union of the then-Lubavitcher rebbe, [Menachem Mendel’s father-in-law Yosef Yitzḥak Schneerson], Levi Yitzḥak became one of the leading rabbinic figures in the Soviet Union. . . . From the pulpit, he called on his community members to keep their dedication to the Torah and its commandments. He collected funds to support the families of Jewish prisoners, ran a network of underground Jewish schools in Dnepropetrovsk, and oversaw the distribution of matzah he received from abroad. In 1936, he was involved with the construction of an illegal mikveh. . . . He led the Ukrainian rabbis’ refusal to sign pro-Soviet statements in the early 1930s.
Authorities did not take kindly to any of this. On March 28, 1939, just days before Passover, the NKVD arrested Rabbi Levi Yitzḥak. Over the next ten months, the venerable fifty-one-year-old rabbi was shuttled among secret police prisons in Dnepropetrovsk, Kiev, Kharkov, and Alma-Ata, Kazakhstan. He was beaten and deprived of sleep. Some of his interrogations lasted fifteen or sixteen hours, followed by a break of two or three hours before starting again. He was charged with being an imperialist spy, funneling money from abroad, and conducting anti-Soviet provocations at home.
In 1992, the SBU—the KGB’s successor in newly independent Ukraine—formally apologized to Menachem Mendel Schneerson for his father’s arrest.
Read more on Chabad.org: https://www.chabad.org/news/article_cdo/aid/4467531/jewish/The-KGBs-Belated-Apology-for-the-Persecution-and-Death-of-the-Rebbes-Father.htm