Pavel's paternal grandparents and all his maternal relatives had been murdered in Auschwitz. Only an uncle, Eugen Ketely, and an aunt, Magdalena Földes née Ketely, and her children survived the Shoah. At Auschwitz, Pavel's uncle was designated as "fit for work" because concentration camp doctor Josef Mengele, with whom he had studied medicine, recognized him at the selection ramp. This saved him from the gas chamber. His wife and child were murdered immediately after arriving at Auschwitz. After the liberation of the death camp, he returned to Czechoslovakia.