Middle Eastern gangs play a prominent role in the Australian underworld. Not all of them are Muslim though. The Lebanese crime families mostly are Muslim (though there are also quite a few gangsters of Maronite Christian background) but there's also Assyrian organized crime and these are Chaldean Catholics.

Outlaw motorcycle gangs are heavy in the Australian underworld as well and their members are largely of British, Irish, Maltese and other European background. I'd even go as far to say that bikers are the number one factor in organized crime in Australia.

Vietnamese gangs have lots of operations in Australia and there are Pacific Islander gangs as well. Pacific Islanders are not as prominent over there as they are in the New Zealand underworld, but they're around and are largely used as muscle for the outlaw motorcycle gangs.

Ndrangheta are also around in Australia; big time operations, but a bit under the radar these days.