South Australian health officials are poised to announce locally-acquired COVID-19 cases after apparent infection from the COVID-hit Northern Territory gold mine.

There are widespread reports a South Australian family linked to an interstate outbreak has fallen ill with the virus and is isolating.

Premier Steven Marshall will provide more details at a briefing at 11.45am (CST) on Wednesday.

However, Northern Territory Chief Minister Michael Gunner has just announced a three-day lockdown for Alice Springs, from 1pm Wednesday, after confirming a miner from the Tanami mine spent most of Friday, June 25, at the Alice Springs airport.

The mine worker then flew on to South Australia.

“He arrived at the airport via a charter flight on Friday morning and remained at the airport between 9am and 3.50pm. He did not exit the airport,” he said.

“On Saturday 26 June, after returning to Adelaide, he got a COVID test. That result was not positive. However, he has since developed symptoms while isolating in Adelaide and four of his five household contacts have now tested positive.”

The Newmont gold mine has now been linked to more than a dozen coronavirus cases across Australia. The infection was brought to the mine by a Victorian worker, who caught COVID in quarantine in Brisbane.

The latest cases will be South Australia’s first local coronavirus infections in about 200 days. The state already has border restrictions with all states and territories bar Tasmania.

Earlier this week, Mr Marshall urged SA residents to get vaccinated, saying the outbreaks across Australia should be sufficient motivation.

“We don’t want lockdowns here – what we want is a very high vaccination rate. There are hundreds and hundreds of appointments available over the coming weeks,” he said.

-more to come