[2] During the Russian Civil War, he was involved in partisan activities against the White movement in South Russia before supporting the communist underground in Turkey and being arrested.

[1] In this capacity, he participated in the persecution of both Veli İbraimov, Chairman of the Central Executive Committee of the Crimean ASSR, and Mamut Nadim, People's Commissar for Education.

[5] On 8 September 1937, Tarhan was arrested and charged with leading an anti-Soviet pan-Turkic organisation,[6] along with Abduraim Samedinov [ru] and Bilâl Çagar [uk].

The arrests of Tarhan, Samedinov, and Çagar served as a basis for an anti-Crimean Tatar campaign as part of the Great Purge.

[6] On 24 November 1956, Tarhan was posthumously rehabilitated by the Soviet government, with the statement on his rehabilitation reading, "Within the Crimean NKVD, where the investigation into the Tarhan case was conducted, from 1937 to 1938 unreasonable arrests, beatings of those arrested, falsification of investigative materials, and other gross violations of the law were allowed.