Im not 100% on this but Asian aros are on a grey list meaning
they are not illegal to own ATM but once they have reviewed if it's a threat to local fish then they will decide if it's illegal to own them.
But it is definitely illegal to import them from overseas...I dont know it's all to confusing here...
Im not sure on this, but yeah correct me please experts...
heres the thing about reviewing the aquarium hobby in Australia..
http://www.lib.washington.edu/msd/norestriction/b56460272.pdf
If your serious about finding an Asian aro in Australia I think this site has a few people that could help you out
http://www.plecofanatics.com/forum/forumdisplay.php?f=57