In 1946, they wrote a comprehensive account of the Holocaust in the Soviet Union, which became known as The Black Book. However, it was not printed since anti-Semitism was gaining momentum in the Soviet Union. The JAC was dissolved, and numerous members were arrested and murdered. Grossmann and Ehrenburg were spared because of their prominence. In 1948, a first edition of The Black Book was published, but it was heavily censored.
It was not until 1994 that the original uncensored manuscript was published in German translation. The book testified to the mass murder of about 1.5 million Soviet Jews.