Have flown in/out of Mildura 6 times in the last 4 weeks, all Sundays, including the day of this incident and can, confirm 2 cases of radio interference. The first about 3 weeks ago was 3 calls over 15 mins of "Annoying planes go away its Sunday", the most recent illegal calls last Sunday involved some extremely racist remarks made towards students of the school and Instructors, ranging fro Go Away to Burn the Chinese like the Jews. All incidents were reported to CASA by myself. At one Stage an inbound REX flight told the person via radio they were notifying local police.