Tasmania has allowed some South Australians to leave enforced quarantine but is keeping its border closed to the mainland state.
The island state had ordered all SA arrivals dating back to November 7 into isolation after a coronavirus cluster in Adelaide.
Tasmania's health department announced on Monday any South Australians who arrived before November 16 would be allowed to leave quarantine.
Anyone who arrived after that date is still required to undertake two weeks' isolation, as are any new arrivals from SA.
People in quarantine with coronavirus symptoms, or those awaiting a test result, are required to stay in isolation regardless of when they arrived.
"Extensive testing in South Australia over the past week has not detected any wider transmission occurring in South Australia (before November 16)," Public Health Director Mark Veitch said.
"Public Health Services will continue to review this situation and provide further advice in the coming days."
Tasmania, which has gone more than 100 days since recording a COVID-19 case, is also closed to Victoria but open to the rest of Australia.
Australian Associated Press