MELBOURNE : Australian health officials on Friday urged the public not to panic or hoard antiviral drugs as fears grew over the spread of swine flu.

Health Minister Nicola Roxon and chief medical officer Jim Bishop made the call because sales of the antiviral drugs Tamiflu and Relenza have increased three or four fold as the disease generates headlines.

The top health officials stressed that the swine flu virus had not been detected in Australia so there was no need to stock up on drugs or food to cope with a possible outbreak.

"It is important for us to make sure we keep a balanced response, and that means being prepared ahead of the game, but also staying calm," Roxon told state radio.

Australia holds 8.7 million courses of Tamiflu and Relenza but they have not been widely released as the country does not yet face a pandemic and it was important not to make a run on the drugs, Roxon stressed.

"If a pandemic were declared internationally there are actually agreements with those producers of those drugs for a distribution arrangement according to need," she said.

"I think it is important for Australia to make sure that we maintain that stockpile for a time if and when things get worse.

"We need people to be respecting the importance of using those antivirals when they're needed and not unnecessarily hoarding them if they are not needed," she said calling for people to "be responsible about this."

Some 140 people have been tested for the virus but none is so far suspected of being infected.

"It's not serious in the country at the moment, there is no virus in the country so people shouldn't be running around worrying about getting infected," chief medical officer Bishop said.

Australia has beefed up border security and has begun using thermal image scanners at its international airports in a bid to detect possible swine flu carriers with elevated body temperatures.

It has also introduced new powers that would allow authorities to detain suspected sufferers if necessary.

But members of the public have been rushing to buy out flu drugs as well as items such as face masks, which have doubled in price in some areas in recent days.

- AFP /ls