One-third of passengers onboard the flight left Sydney airport before being screened.
In a major breach of health protocols, 137 passengers arriving at Sydney airport from Melbourne were allowed to disembark without being screened for coronavirus.
The passengers flew onboard Jetstar flight JQ250 and touched down in Sydney just before 7pm on Tuesday.
NSW Chief Health Officer Kerry Chant said the health team responsible for the screening were occupied with another airplane at the time of the flight's arrival.
"There was an issue at the airport where passengers were disembarked when the health screening team were screening another airline," Dr Chant told reporters on Wednesday.
"The airport has now put in protocols to ensure that the health teams are there and able to do the screening and no one's allowed to disembark before that happens."
In a statement, a spokesperson for NSW Health said airline staff allowed passengers to leave the gated area, breaking screening protocols.
Once alerted to the breach, health officials, airport staff and police acted to bring 89 of the 137 passengers back to the gate to be screened.
Forty-eight passengers had already left the terminal, with NSW Health making arrangements with 45 travellers to conduct screenings.
Three remaining passengers who refused screenings have been referred to NSW Police.
"If anyone has travelled in breach of any orders we will refer them to police and take the appropriate action depending on whether anyone is symptomatic to ensure that the community is protected," Dr Chant said.
Victorian health authorities are also conducting temperature and ID checks for all travellers departing the state, so the passengers should have been screened prior to taking off.
A spokesperson for Jetstar said the airline has helped to locate passengers and provided a flight manifest.
"Together with Sydney Airport, we have refined our disembarkation procedures to prevent this situation occurring again," the spokesperson told SBS News.
Residents in affected public housing towers who need access to support and assistance should call the Housing Call Centre on 1800 961 054. If you need a translator, first call 131 450. Both services are 24/7. More information can be found here.
People in Australia must stay at least 1.5 metres away from others. Check your state’s restrictions on gathering limits.
If you are experiencing cold or flu symptoms, stay home and arrange a test by calling your doctor or contact the Coronavirus Health Information Hotline on 1800 020 080.
News and information is available in 63 languages at sbs.com.au/coronavirus