Some 50,000 CDs of Christmas carols sent to households in Germany by a children's charity actually contained the words to pro-Nazi songs sung by the Hitler Youth movement, German public radio NDR reports.
Spokesman for the SOS Children's Villages charity, Roger Damm, told NDR the CDs could have been hacked by a far-right group.
Both the German branch of the charity and the production company that made the CD have lodged a complaint in Munich for incitement to hatred, Damm said.
Households had been informed of the incident, Damm said.
Hitler Youth was a paramilitary Nazi youth group aimed at training up members to serve the Third Reich.