Trans-Tasman travel bubble: South Australia open to New Zealanders with no quarantine requirement

South Australia is the latest state across the ditch to open its borders to New Zealand travellers.

The borders opened effective immediately on Tuesday afternoon, ABC reports.

It follows five Kiwis arriving unexpectedly in Adelaide on Sunday who were placed into hotel quarantine at their own expense. New Zealanders currently in quarantine will be allowed to leave.

The state's regulations previously stated that New Zealanders couldn't travel to South Australia without self-quarantining for 14 days.

South Australia Police Commissioner Grant Stevens said the state would also be "happy to accommodate" direct flights from New Zealand.

"I'm pleased to be able to announce that New Zealand people arriving in South Australia, they will no longer be required to quarantine," he said on Tuesday.

The initial travel bubble was only open between New Zealand and the states of New South Wales and Northern Territory. However, this didn't stop at least 100 Kiwis travelling to other parts of Australia after arriving in Sydney.

Victoria Premier Daniel Andrews said on Monday his state's borders were also open to New Zealanders. He said even though Victoria didn't want to be part of the travel bubble, it doesn't have restrictions on incoming domestic flights while its state borders are open to the rest of Australia.

Stevens said he'd been in contact with New Zealand authorities and he felt a "level of comfort" in making the decision to open South Australia's border.

"We hadn't had specific advice in relation to the status of COVID-19 in New Zealand [when the travellers arrived]," he said.

"The health advice has been assessed by direct communication through our Chief Public Health Officer with New Zealand authorities and there is a level of comfort there in terms of the extent of COVID-19 that allows us to make this decision."

He said while it was unfortunate some New Zealanders had been inconvenienced for entering the state, he "didn't apologise" for taking steps to ensure the safety of South Australian residents.

"These people will have been inconvenienced for a relatively short period of time, whilst we made a proper assessment of the risk to South Australia."