 On a visit to Berlin, Gustaf went straight from a meeting with Hitler to a tennis match with the Jewish player Daniel Prenn.During World War II, he interceded to obtain better treatment for Davis Cup stars Jean Borotra of France and Gottfried von Cramm of Germany, who had been imprisoned by the German Government.Allegations of a love affair between Gustav and Kurt Haijby led to the court paying 170,000 kronor under threat of blackmail by Haijby.