The exposure comes following the setting up of the Independent Historical Commission by Bertelsmann to investigate its Nazi past.
The commission found that the previous claims by Bertelsmann, that it was merely a victim of the Nazis, is a lie. The media group had claimed that the Nazis tried to close it down, but according to the commission it was only threatened with closure because it might have been engaged with snuffing out the competition and not because of any qualms about Nazi murder, torture or the death camps.
The commission was set up in 1999 following Bertelsmann's acquisition of US publishing giant Random House in 1998 and allegations about its Nazi past.
Bertelsmann is just the latest German firm to face questions about its Nazi era past. Recently, Deutsche Bank, Volkswagen and DaimlerChrysler have all been in the spotlight.
The media firm's success under the Nazis paved the way for it to become a major player in the post-war era. The company benefited under Hitler's regime, winning large publishing contracts supplying books to the Nazi German army during the Second World War.
According to the report: "In 1945, the legend that C. Bertelsmann was closed down because of resistance to the Nazis smoothed the way for the occupation authorities, promptly granting the firm a new licence to publish."
In response to the report, Bertelsmann issued a statement expressing regret for its Nazi-era business and for later "inaccuracies" in its corporate history.
IHC chairman Saul Friedlaender said: "Bertelsmann published a variety of papers and books that clearly had anti-Jewish bias."
This books included propaganda as 'The Christmas Book of the Hitler Youth' and a long-running 'Exciting Stories' series, which were supplied to German soldiers and included anti-Semitic stereotypes and rants against the Jews.
Damagingly, the commission found that Heinrich Mohn, Bertelmann's chief under Hitler, donated to the SS, whose units were among German's most barbarous, as well as being used to run concentration camps.
The commission also revealed that Bertelsmann used Jewish slave labour in printing processes in Riga, Latvia, and possibly in Lithuania.
In a statement, Bertelsmann chairman Gunther Thielen said: "I would like to express our sincere regret for the inaccuracies the commission has uncovered in our previous corporate history of the World War Two era, as well as for the wartime activities that have been brought to light."
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