Klaus’ mom was a Rothschild. Bad seed all the way around.
This bio says his dad was Fred Schwab. With documents and pictures.
Fred Schwab and Marianne Schwab, née Rothschild
“My mother taught me not to hate”
by Angelika Rieber
Fred Schwab was born in Frankfurt. In 1935, he managed to leave Germany. His wife Marianne, née Rothschild, came from the town of Bad Homburg. After the 1938 Pogroms, she fled to the USA via Britain. The couple visited their former country as guests of the City of Frankfurt, to which they kept close emotional ties. Both returned often, met former classmates and spoke at schools. Their daughter Madeleine was invited by the City of Bad Homburg in 2013. She attended the opening ceremony for a deportation memorial in her mother’s home town. From here, her grandparents had been deported to the Theresienstadt concentration camp in 1942.
Moar at link
http://www.juedisches-leben-frankfurt.de/en/home/biographies-and-encounters/biographies-s/family-schwab.html