Security guards had found her handbag near a museum in Brisbane yesterday afternoon with her passport and driver's licence inside.
"We just hope she has some cash in her pocket and that she hasn't been abducted and the handbag has been thrown away and the cash taken out of it.
"She is in a country now of 24 million people, where at least in New Zealand it was 4 million people and it was a bit smaller, we are beside ourselves.''
He was considering flying to Brisbane to join the search.
"It's a bit like look ing for a needle in a haystack. We don't know what to do, that's the problem.''
Brisbane police was reviewing CCTV footage and the results were expected soon.
The only people she knew in Australia was her parents in Melbourne, he said.