Соловецкий лагерь особого назначения
In 1926 he decided to stay in East Belarus after a conference in Minsk. Several months later he was arrested by the NKVD and sent to Solovki prison camp. He spent seven years in the Gulag; in 1933 he was exchanged for Branislaw Tarashkyevich, a West Belarusian politician and linguist held in Polish prison.