The documentary series has previously uncovered details of how children were abused at the spas and routinely beaten, sedated, and injected with psychotropic drugs.
In a new report broadcast on Monday night, it investigates how senior former Nazis were in positions of authority at spas where children were abused until as recently as the 70s.
Hugo Kraas was a senior SS general and commander of the Hitler Youth Panzer Division. He knew Hitler and Goebbels personally.
According to new research for the documentary he remained a staunch Nazi until his death, and attended the funeral of a fellow SS officer and convicted war criminal in 1966 wearing medals he was awarded under the Third Reich.
Yet in 1969 he was appointed director of a spa where children suffered abuse in the North Sea resort of St Peter-Ording.
Werner Scheu, another former SS officer, was allowed to run a spa on the nearby island of Borkum in the Fifties.
He was later convicted of war crimes over the shooting of 220 Lithuanian Jews and sentenced to life in prison.
A woman who was sent to Scheu's spa as a child told the documentary how she was forced to stand barefoot on the cold floor for hours at night as a punishment. On another occasion she was locked in the sauna.
Albert Viethen, a former SS doctor, served as medical director of a children's spa in the Bavarian Alps in the 50s.
In 1963 he was prosecuted on charges of transferring children to a Nazi eugenics programme during World War II. He escaped conviction by claiming ignorance of the children's fate.
"You actually had to watch all the time that you weren't pushed or punched, that you weren't knocked over," said a man who was a child when sent to the spa where Viethen was medical director. "That meant that I was pretty much a bundle of nerves. The time I spent there was the worst time of my life."
The German authorities have pledged to investigate abuse at the health resorts.
"We are looking into some dark places," Manfred Lucha, a spokesman for regional health ministers, said.
