Health authorities are scrambling to contact passengers on five flights after a Sydney-based Virgin cabin crew member tested positive to COVID-19.
They tested positive after a rapid result test on Saturday night, Virgin says.
The five flights on Friday and Saturday took passengers either to or from Brisbane, Melbourne, Sydney and the Gold Coast.
"The crew member is now in isolation, and Virgin Australia is rapidly contacting all team members who are close contacts," the airline said in a statement.
"Virgin Australia is requiring those crew members to cease flying, get tested and isolate.
"All passengers on flights the crew member operated will be contacted by health authorities and advised on the correct protocol."
The new comes as Greater Sydney and surrounding areas were placed in a 14-day lockdown due to a worsening COVID-19 outbreak.
The airline says the crew member is a close contact of a COVID-19 case from a known cluster in Sydney, but was unaware of the fact until after completing their last flight on Saturday.
"The aircraft this crew member has flown on are being deep cleaned overnight, as are any Virgin Australia spaces the crew member visited," it said.
NSW Health says the five flights are of concern as the crew member may have been infectious during that time.
They also had an overnight stopover in Melbourne on Friday night, staying at the Holiday Inn Express Southbank.
Virgin says the crew member always wore a face mask while onboard and when interacting with the public and adhered to infection control and COVID protocols.
It says given NSW's border restrictions in place, most of the flights, with the exception of VA334 between Brisbane and Melbourne on Friday, were carrying limited numbers of passengers for the purpose of essential travel only.
Virgin says all its services this weekend are continuing to operate as normal.
THE AFFECTED FLIGHTS:
Friday, June 25
* VA939 Sydney-Brisbane
* VA334 Brisbane-Melbourne
Saturday, June 26
* VA827 Melbourne-Sydney
* VA517 Sydney-Gold Coast
* VA524 Gold Coast-Sydney