 He was engaged in agricultural research at the International Agrarian Institute for six years, but also worked in the Hungarian section of the Comintern.He was expelled from the party on 8 January 1936 and worked for the Soviet Statistical Service from the summer of 1936 onward.Under the codename "Volodia", Nagy served the NKVD secret police as an informer from 1933 to 1941, giving up the names of over 200 comrades, mostly from the Agrarian Institute, who were then arrested and in at least 15 cases executed by the secret police.