Following the Soviet occupation of Hungary, Lakatos was interrogated several times in Kiskőrös. He was released from prison in January 1946 and thereafter appeared as a witness in war crime trials against the Arrow Cross Party and other pro-Nazi former officials before the so-called People's Tribunal of Budapest. In the forthcoming years he lived in his estate in Érd. His military pension was revoked by the Communist authorities and his lands were also confiscated in 1949. Following that he moved to Budapest where he worked as a book illustrator and silk painter, and lived in poor financial circumstances. His daughter emigrated to Australia in 1956, when the failed Hungarian Revolution briefly allowed people to emigrate from Hungary. Following his wife's death in 1965, the authorities permitted Lakatos to travel to Adelaide where his daughter lived since 1957. He died there a decade later, in 1967.