Terror suspect seized from plane carrying 'beheading images and $30,000'

The terror suspect dragged off a plane at Melbourne airport by Australian Federal Police was reportedly carrying images of beheadings and the Islamic State flag, as well as up to $30,000 in Australian bills.

He was travelling to the Middle East with family members who were not suspected of any terror-related activities but who chose not to continue their flight, the Herald Sun has reported.

The man was released from custody after being questioned, but it is understood he is still under investigation.

The new Australian Customs and Border Protection counter-terrorism units were introduced last week to monitor the movements of people on the national security watchlist.

So far they're based at Sydney and Melbourne international airports but eventually will be stationed at airports across the country.

They'll cost nearly $50 million over the next four years to run and are part of the $630 million in beefed up security measures promised by the Abbott government to counter home-grown terrorism.

An extra 80 specialist Border Force officers will work in tandem with these units.

The AFP will also receive an extra $6 million to divert and monitor radicals returning to Australia while two dedicated teams will disrupt domestic extremist activities.

There are believed to be about 60 Australians fighting in the Middle East in conflicts in Iraq and Syria, while 15 others have already been killed in the fighting.

Additional reporting by AAP.