Australian authorities to blame after New Zealanders snuck into Melbourne - international relations expert

An international relations expert believes the 17 New Zealanders who snuck onto a flight to Melbourne made an innocent mistake because the state restrictions across Australia are complex.

The Victorian government confirmed the 17 passengers arrived at Melbourne Airport on Friday night after first landing in Sydney from New Zealand. They then slipped through domestic security to board the Melbourne-bound flight.

There is a travel bubble between New Zealand and the states of New South Wales and Northern Territory and arriving passengers aren't required to enter quarantine.

University of Auckland Associate Professor Stephen Hoadley said he doesn't believe the Australian authorities are doing their job.

"That information [about state restrictions] should have been available at check-in at Auckland airport and there should have been notices at Sydney Airport as well," he said.

There were three quarantine-free flights from Auckland to Sydney on Friday run by two companies - Qantas and Jetstar.

Qantas told Newshub it has checked their passenger lists and none of the 17 were on its flights. 

Before the breach, the New South Wales Premier Gladys Berejiklian thought the system was going to work. 

"This is a safe thing to do and the right thing to do," she said.

But Victorian Premier Daniel Andrews said he doesn't know who or where the escapees are.

"They left the airport within really minutes of having only arrived. Our offices have absolutely no power to stop someone detain someone," he said.

"We are still waiting, and I don't know why we're still waiting, for Australian Border Force, for the passenger cards. As soon as we get those detail we will be visiting each of those people."

He warned any other Kiwis heading across the ditch that he doesn't "want a repeat of this".