Australian Health Minister Nicola Roxon said on Sunday the government expected the health authorities to announce more cases of A/H1N1 flu later in the day.
With two more cases adding on the list, a total of 16 cases of the A/H1N1 virus have been confirmed in Australia so far.
Roxon said with quicker testing turnarounds, she anticipated that number would grow.
"We expect to have a number (of suspected cases) further confirmed later today," she told the Nine Network on Sunday.
The Victorian health authorities confirmed Australia's 16th A/H1N1 flu case and the state's 11th on Sunday when a 15-year-old boy from Melbourne's northern suburbs was diagnosed with the disease.
Roxon said it was a concerning development in the spread of the virus.
"We do have a slightly worrying development in that we have several cases where we cannot identify where they might have got the disease from," she said.
"They're not travelers; they're not immediate contacts of confirmed cases."
But, Roxon said, it was unlikely the disease had been lying dormant in Australia long before its worldwide outbreak last month.