Born into a Jewish family in Warsaw, he was a member of the "Gwiazda Warszawa" Boxing Club in 1929–1939. He won the bronze medal in the Flyweight class at the 1934 European Amateur Boxing Championships in Budapest. In 1933 he won the Polish champion title. He represented Poland in many matches: POL vs. HUN (1934, 1935), POL vs. USA (1934), POL vs. CZE (1934), POL vs. GER (1934, 1935, 1938), POL vs. NOR (1937), POL vs. DEN (1937), POL vs. ITA (1938), POL vs. FRA (1938), POL vs. SUI (1938), POL vs. EST (1938), POL vs. SWE (1939), POL vs. FIN (1939), scoring +15 –0 =1. He played also for Warsaw in duals against Dublin (1937), Vienna (1939) and Italy (1939), scoring +2 –1 =0. Rotholc won all fights except two, one drew and one loss with an Italian boxer Guido Nardecchia.