A Qantas crew member who has tested positive for coronavirus flew from Darwin to Sydney without quarantining just one day after arriving back in the country on a flight from Paris.
Qantas medical director Ian Hosegood says the man had crewed flight QF176, which departed Charles De Gaulle Airport last Wednesday and arrived in the NT on Thursday.
He then immediately caught domestic flight QF841 Darwin-Sydney on Friday before self-isolating at home in NSW.
The man developed COVID-19 symptoms on Monday and tested positive before he was moved into hotel quarantine.
Dr Hosegood says under government rules at the time, the air crews didn't have to go into quarantine immediately but could fly interstate to self-isolate at their homes.
"This was in line with government-approved protocols," he said in a statement on Wednesday.
"Since then the protocols have changed and operating crew won't be travelling on normal domestic flights after operating international repatriation flights."
NT Health Minister Natasha Fyles said the man had very limited contact with the community, stayed one night in the designated Hilton Hotel and wasn't believed to be infectious while he was in Darwin.
She defended the rules that permitted him to travel before quarantining as practical for businesses.
"So reassure Territorians, there's strict protocols around the different situations, the unusual situations, that we may have to have to allow business in some sense to happen," Ms Fyles said.
She said the rules tried to balance the need to protect Territorians and Australians from the virus with the free flow of freight and medical equipment into the country.
"This is something that the jurisdictions continue to work (on) at a Commonwealth level, and we will continue to evolve that, and if we need to put in place further precautions we will do so," she said.
Dr Hosegood said the Qantas was working with the federal and NSW health departments to find out how the crew member contracted the virus.
Contact tracing is also underway in the NT and NSW, with other crew members being traced as well.
Dr Hosegood said the source of the infection is a mystery because the man didn't have any symptoms on either the repatriation flight or the domestic flights and he was wearing a face mask at all times.
He also said the Qantas crew had remained in their rooms under supervision during their layover at Charles De Gaulle Airport.
"We are not aware of any compliance breaches," Dr Hosegood said.
"Despite operating well over 100 international flights back from COVID-hotspots - including Wuhan, the United States and Europe - this is the first Qantas crew member who has contracted the virus since late March."