Otto Braun, the son of a lawyer, studied at the Hochschule für Bodenkultur (now called the University of Natural Resources and Applied Life Sciences) in Vienna’s 18th district after completing his A-levels. In 1924, he passed the agricultural state examination and was henceforth entitled to use the professional title of engineer. He lived at Grünentorgasse 18 in Vienna’s 9th district, until his emigration. In the mid-1920s, he likely completed agricultural internships in Lower Austria before moving to Buenos Aires, Argentina, in August 1926 to devote himself to archaeological, botanical and agronomic studies. After a brief visit to Vienna in 1932, he left for Camargo, Bolivia. Shortly before his departure, on 15 September 1932, he handed over 61 ethnographic objects from Bolivia to the Museum für Völkerkunde (MVK, now the Weltmuseum Wien) as "loans for the duration of one year". In 1933 he married Mercedes Trujillo in Bolivia.

Due to his Jewish heritage, Otto Braun's original plan to return to Austria was no longer an option after the "Anschluss" to the German Reich. His mother, Gisela Braun, born in Pécs, Hungary on 11 February 1878, Hungary, a sister of Alexander Zirner, managing director of the Gebrüder Zwieback department store on Kärntnerstraße in Vienna’s 1st district, had been a widow since 1925. In June 1938, she applied for a licence to export removal goods to Buenos Aires via the forwarding agent E. Bäuml. Ethnographic objects did not appear among the items listed. At around the same time, she endeavoured to have the items on loan from the MVK returned. On 11 June 1938, the then director Fritz Röck wrote on a postcard to Gisela Braun that the objects were ready for collection, but the card was not sent. A note added a few days later states that the MVK had "correctly taken over" the collection. The museum eventually handed over 35 objects to Braun, while the rest remained in the museum. Gisela Braun was able to flee to South America at the end of September 1938, where she lived with her sons Otto and Robert in Buenos Aires. Otto Braun later found work on vineyards in Culpina near Camargo in Bolivia. A "donation" by Otto Braun to the MVK in 1943 – a robe pin from a shaft stool grave in Bolivia – was made at a time when neither Gisela nor Otto Braun were in Vienna. Between 1948 and 1975, the MVK inventoried the objects with the indication of origin "Otto Braun Collection", including the loans that remained in the museum. Gisela Braun's moving lift had been confiscated and sold by the Vugesta in 1940.

In 2009, the Art Restitution Advisory Board recommended the restitution of the 26 ethnographic objects from the Otto Braun Collection that remained in the MVK. It assumed that even if the objects had been acquired by the museum by legal transaction in 1938, it could be assumed that they had been seized, as such a transaction would have taken place in direct connection with the flight of Gisela Braun, who was persecuted as a Jew, and the impossibility of Otto Braun's return. In 2012, the MVK purchased the ethnographic items from the heirs of Otto and Gisela Braun.