A suspected French extremist travelling with cans of mace was caught trying to enter Australia two days after the Paris terror attacks.
Attorney-General George Brandis said the French national was detained at Melbourne airport on November 15 and deported.
"What I think this case illustrates is the care which the Australian government takes to ensure that everyone that arrives in Australia is subject to appropriate scrutiny," he told ABC radio on Wednesday.
Senator Brandis said the man had three cans of mace as well as extremist literature.
Everyone who comes to Australia is assessed by authorities and where there is an unacceptable level of risk, measures are taken, he said.