Gustav Rochlitz moved to Paris in 1933, where he established numerous contacts in the Paris art world. Once the war had broken out and under the Occupation, Rochlitz took advantage of his German nationality and the growing demand for artworks in order to make his fortune.
He rapidly became a regular visitor to the Jeu de Paume. He collaborated with representatives of the ERR over a four-year period, during which he sold his bounty to his fellow countrymen, and to collectors from the Parisian and European markets.
Arrested in Germany in December 1945, then imprisoned, he was condemned to a three year prison sentence on 28 March 1947 on the grounds of economic collaboration. His assets were also seized. He was pardoned by the french president in 1950 and set about reclaiming his seized assets. He died at the age of 83 in 1972.