I imagine you are familiar with the story from Southern Brazil whereby Mengele is connected to Candido Godoi, the famous "twin capital of the World", right?
Cândido Godói is a municipality of 6,641 inhabitants in the state of Rio Grande do Sul, Brazil near the Argentine border, famous for the high number of twins born there. The twin phenomenon is centered in Linha São Pedro, a small settlement in the city of Cândido Godói, in an ethnically homogeneous population of German descent.[3]
https://en.wikipedia.org/wiki/Cândido_Godói
Incidentally, Mengele's wife was the high school teacher of a friend of mine from Sao Paulo.