Checks nab suspect French extremist

Nothing suggests a suspected French extremist who tried to enter Australia with cans of mace was connected to the terror attacks in Paris, the federal government says.

Immigration Minister Peter Dutton isn't aware if the man, who was detained then deported from Melbourne last month, had any links to the November 13 shootings in the French capital which killed 130 people.

"We don't have any information ... to link it to the Paris attacks," he told reporters in Brisbane on Wednesday.

The French national was caught with three cans of mace as well as extremist literature when he flew into Melbourne on November 15.

He was stopped by officers from the counter-terrorism unit, who try to identify people who raise "red flags" at customs and immigration points.

Counter-terrorism unit officers across the eight international airport have conducted 82,500 real-time assessments in the past six months.

"The fact that they were able to detect this person early on in his arrival process I think is impressive," Mr Dutton said.

Other people with EU passports would also have been stopped, he confirmed.

The domestic terror threat level is currently rated a `probable', meaning the public should exercise caution.

Heading into the new year, Attorney-General George Brandis said there were a number of challenges in combating terrorism.

The first was making sure Australians realised the "real and present" level of threat.

"This is not something that the government is saying merely to scare people," he told ABC radio.

"This is a judgment made not by politicians, but by the director general of ASIO in consultation with security professionals."

He reassured Australians security agencies are doing all they could to keep people safe.

Acting Opposition Leader Tanya Plibersek thanked agency workers for their efforts in stopping the Frenchman.

"I was very pleased to see that our security and intelligence agencies picked up someone who was suspected of poor intent coming into Australia," she told reporters in Sydney.

"It shows the effectiveness of the people that we have working here."