Australia has a very dark racist past. In fact after white invasion of their continent the Aboriginals (here for 40,000 years) fought back greatly but were slaughtered in what can only be described as genocide.
Unbelievably, it wasn't until the 1960's that Aboriginals were even granted the right to vote (not by a plebiscite BTW but an act of parliament) and counted in the population.
I suspect Australia's history after British settlement has been whitewashed, literally. Perhaps many of the atrocities committed by the British over more than 100 years will never see the light of day in modern history, but live on only in the generational stories passed down by Aboriginal elders.