South Australia has recorded two new coronavirus cases including a young man who returned a "weak positive" result after travelling into the state from NSW.
Chief Public Health Officer Nicola Spurrier said the man in his 20s was aboard a flight from Darwin to Sydney on December 18 that contained an infectious person.
But she said the man was not seated near the person and the positive result was likely due to an old non-infectious case.
"It's my understanding it is likely to be an old infection therefore nobody in South Australia is at any risk," Professor Spurrier said.
Prof Spurrier said the health department was working to confirm further details and she was awaiting verification of his result.
The man travelled from Sydney to Wodonga, spending some time in rural Victoria, and crossed into SA at the Yorke Peninsula on Monday.
He is in quarantine along with five close contacts as a precaution.
Prof Spurrier said the man was in Victoria at the height of their outbreak but never showed symptoms.
The second case is a man in his 70s who is in a medi-hotel after returning to SA from Doha on December 18.
