Fourteen passengers have been detained in Melbourne after they arrived from New Zealand under the transtasman bubble arrangements.
The ABC understands the passengers flew to Sydney and got a connecting to flight to Melbourne.
Melbourne is currently not accepting international travellers, with the travel bubble only including NSW and Northern Territory.
Australian Border Force (ABF) has been contacted for comment.
Travellers on the first commercial flight from New Zealand in seven months landed in Sydney this afternoon - in the first phase of a transtasman travel bubble.
There were emotional scenes at Sydney International Airport as families were finally reunited after the bubble opened overnight.
Passengers on board the Air New Zealand flight touched down at midday.
Kiwi passengers will not have to enter hotel quarantine upon arrival. A Jetstar flight and a Qantas flight were also due to land today.
The arrivals mark a welcome development in international travel arrivals, with Australia's border being closed to international arrivals since March.
Under the deal between the two nations, New Zealanders will be allowed to travel quarantine-free into NSW and the Northern Territory if they have not been in a Covid-19 hotspot in the previous 14 days.
Upon arrival in Australia, passengers will be separated into green and red zones at the airport, demarcating quarantine-free flights and travellers subject to a mandatory 14-day quarantine.
Currently, it is a one-way bubble. Australians will be able to travel across the ditch at a later, still undetermined date.
Reaction on social media was swift.
"Why anyone would come to melb at this time I don't know," wrote another, in reference to the months-long Covid-19 restrictions in the city, after it was affected by a severe second wave of the virus.
Another was more welcoming, posting "Welcome to Hotel Melifornia."
Earlier on Friday afternoon, Scott Morrison said about 230 New Zealanders had arrived in Sydney.
"We have already welcomed our first Kiwis back to Australia for a holiday. That's fantastic," the Prime Minister said.
"Some 230, I understand, were on the flight this morning that has arrived, and I think is just going through customs now as we speak, and there are others who will be coming."
"We welcome those Kiwis, Kia Ora to those Kiwis who've joined us today, I hope you enjoy your holiday in New South Wales or the Northern Territory or the ACT and tell your friends and we're looking forward to seeing more of you."