But after reading documents kept by the family, the younger generation began to ask questions and commissioned a University of Munich historian in 2014 to examine the Reimann history more thoroughly, Harf said.
The expert presented his preliminary findings to the Reimann children and grandchildren, as well as Hanf, several weeks ago, he said.
"We were all ashamed and turned as white as the wall," he said. "There is nothing to gloss over. These crimes are disgusting."
In addition to Krispy Kreme Doughnuts and Pret a Manger, the Luxembourg-based JAB Holding Co. has controlling stakes in Keurig Green Mountain, Peet's Coffee & Tea, Caribou Coffee Co., Panera Bread and other companies.
Many German companies have acknowledged using slave labourers during the Nazi era and have conducted their own independent investigations.
In 2000, the German government approved a 10 billion mark (about 5.1 billion euro) fund to provide compensation, with half the money coming from companies like Bayer, Siemens, Deutsche Bank, Daimler-Benz, Volkswagen, and AEG.
Bild reported that even before the Nazis came to power, the Reimanns donated to the paramilitary SS.
During World War II, the company used forced laborers in its industrial chemicals company. It was not clear how many were used overall, but Bild said in 1943, 175 forced laborers were being used, about 30 percent of its workforce.
In addition to Russian and other Eastern European civilians, the company used French prisoners of war — about whom Reimann Jr. complained in a letter to the Ludwigshafen mayor in 1940 that they weren't working hard enough.
After the war, the two were investigated by the occupying Allied powers and initially banned by the French from continuing their business activities but then had the judgment overturned by the Americans, Bild reported.
Harf said the family would donate 10 million euros ($16.4m) to a not-yet-determined charity as a gesture, and once the historian's report is complete, it would be released to the public.
"The whole truth must be put on the table," he said.
- AP