A passenger on board Thursday's repatriation flight into Canberra has tested positive for COVID-19, ACT's health authority has confirmed.
The passenger, a woman in her 20s, was aboard a Singapore Airlines flight carrying 120 Australians who had been stranded overseas, touching down in the nation's capital on Thursday afternoon.
She first tested positive to the virus a month ago, authorities say, and was no longer experiencing acute illness.
"She returned a low positive result during routine testing on day one of mandatory quarantine. We believe this represents her old overseas-acquired infection. She is not considered infectious and contract tracing will not be required," an ACT Health spokesperson said.
"No other COVID-19 positive tests have been reported from returned Australians from the government-facilitated flight on 26 November."
They remain in a mandatory two-week hotel quarantine in Braddon's Pacific Suites and ACT Health has said the risk to hotel and government staff is "extremely low".
The ACT has undertaken 487 COVID-19 tests in the 24 hours leading up to Saturday afternoon.
Staff at the hotel will be screened daily and are subject to a COVID-19 test every seven days through a symptom surveillance program, ACT Health said.
It comes as a diplomat tested positive to the virus on Friday after first arriving in Sydney International Airport.
The woman in her 50s made the trip to Canberra from Sydney in a private vehicle and the risk of community transmission is considered low.
The two cases, both within quarantine, mark the territory's only known active cases, bringing the total number up to 117 since the start of the pandemic.