 Thanks to his contacts with the Italian legation in Lithuania, he helped Poles escape the conflict.After the annexation of Lithuania by the Soviet Union in June 1940, Tyszkiewicz was arrested and taken to Moscow where he was invited to collaborate with the NKVD, an offer he rejected requesting instead a "laissez-passer" to Italy.He was released from Lubianka Prison in October 1941 and made his way to the General Anders' army being formed then in preparation for a mass exodus from the USSR.