I would think that both DG and Lyndal are 100% correct in what they say.

A few years ago when we were applying for a residence visa for my wife we had to submit some supporting documents that were written in Chinese.

We had to have those translated, and the translations stamped, by an accredited translator for the immigration dept to accept them

So I would think the ATO would be no different in this regard.

These services do not come cheap by the way. I think you can expect to pay in the vicinity of $100 per page.