The videotape of a masked militant with an Australian accent warning on Arab television of terrorist attacks on the West "looks authentic", says Australian Foreign Minister Alexander Downer.
The news comes amid growing concerns in Australia that it could be targeted by extremists for its support of the United Statesin Iraq and as Prime Minister John Howard considers tougher anti-terror laws.
The videotape shows a man, wearing combat gear and holding an automatic rifle, boasting about a recent attack that killed American troops in Afghanistan and slamming US President George W. Bush and British Prime Minister Tony Blair over their involvement in Iraq.
The video, being studied by Australia's intelligence agencies, also featured blurred footage said to be of a rocket attack on a helicopter that killed 16 US soldiers in June.
The man, against a backdrop of trees, claimed a group of al Qaeda fighters carried out the operation.
"The animals under Islam will not just let you kill our families in Palestine, Afghanistan, Kashmir and the Balkans, Indonesia, the Caucuses and elsewhere.
"It is time for us to be equals. As you kill us, you'll be killed. As you bomb us, you will be bombed."
Mr Downer said the tape "looks authentic", but it could not be confirmed until the recording had been assessed by Australian security agencies and the federal police.
"Bearing in mind we do have a very small number of Australians who are jihadists, who have joined the jihad movement, have trained with al Qaeda, we can't rule it out that it is an Australian," the Foreign Minister said.
"We'll try to identify him but first of all, you know, obviously you have his voice. Visually he has a balaclava on so that will be extremely difficult to do. But experts will be having a look at that."
The Age newspaper said a forensic linguist estimated the man was aged 18 to 30 and born in Australia of foreign parents.
"He is born here, but with ethnic parents, with non-English-speaking background parents," said Georgina Heydon, a lecturer at Monash University.
"He is young, most likely 18 to 30, but I couldn't tell you what ethnicity."
