Spokesman of the Reimann family, Peter Harf, told Bild am Sonntag of plans to give 10 million euros to charity after learning of their elders' support for the Nazis and their company's use of forced labour during the war.
“Reimann senior and Reimann junior were guilty. The two entrepreneurs have both passed away, they belonged actually in prison,” said Harf.
Albert Reimann senior died in 1954 and his son in 1984.
The company they left behind, JAB Holding, is today a behemoth that owns household brands ranging from Clearasil to Calgon.
With wealth estimated at 33 billion euros, the Reimann family is believed to be Germany's second richest.
Harf said the family began digging into their dark past in the 2000s, and in 2014 decided to commission a historian to produce a thorough study into their ancestors' ties to Nazism.
The family plans to make public a full account when the book by the historian, Paul Erker of Munich University, is finished, said Harf.
Quoting letters and archival documents, Bild am Sonntag said Reimann senior was a willing donor to Hitler's SS as early as 1931.
His company was in 1941 deemed a “crucial” firm in the war, as it produced items for the Wehrmacht and the armaments industry.
In 1943, the company was using as many as 175 forced labourers, and employed a foreman who was known for his cruel treatment of the workers.
Harf, who confirmed the conclusions drawn by the Bild report, said there had been no known efforts to provide any compensation to the forced labourers.
“But we have since talked about what we can do now,” he said.
“We want to do more and donate ten million euros to a suitable organisation.”
Many of Germany's biggest companies have over the decades confronted their Third Reich history.
Among them is Volkswagen, which used concentration camp internees and prisoners of war as slave labour in its factories during WW2.
In 1938, Hitler himself laid the foundation stone for the first Volkswagen factory in Wolfsburg in northern Germany, tasked with building an affordable car for all Germans — which would go on to become the iconic Beetle.