The laws in Belarus say the following:
You can drive to Belarus if you have an International Driving Licence and documents showing that you are the owner of the car – originals not photocopies.
Source: Belarus - Official Website of the Republic of Belarus
It means that:
1. You can drive in Belarus without an International Driving Permit as long as you have a valid Australian driving license written in English, includes your driver photo, and is in accordance with the International Road Traffic Convention of 1968 and Geneva Road Traffic Convention of 1949.
2. You will not need an International Driving Permit if you meet the requirements mentioned above.