An Air New Zealand crew member is concerned the current COVID-19 protocols for staff don't adequately protect the wider community.
It follows a crew member testing positive for the virus on Sunday after landing in Auckland from Tokyo, Japan on February 28.
Japan is classified as a 'medium risk' destination, and crew returning from there need to get a test within seven days of touching down. But that's the only local requirement.
The infected crew member went to the Auckland Airport Countdown after initially returning a negative result.
The positive was revealed after a second test, which epidemiologist Michael Baker says could mean they were incubating the virus.
"And given there's no controls on their activities, there is the potential for them to infect other people in New Zealand and start an outbreak."
Air crew who travel to high-risk locations like San Francisco or Los Angeles must isolate on return and be tested before resuming normal activities.
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Baker says that system could be extended to include crew from medium-risk countries. Air New Zealand doesn't think this is needed as only a handful of air crew in total have tested positive.
"I think the benefit would be very small. We've only seen three cases in 11 months," says Dr Ben Johnston, Air New Zealand's chief medical officer.
But there's also concern about other international routes.
Crew working on flights out of Australia don't have to isolate when they land, but they are required to have a test within seven days of arriving. However, they're frequently asked to work domestic flights the next day, for example flying to Rotorua or Queenstown. There's no requirement they're tested before heading off on those local flights.
It's a situation a current Air New Zealand crew member says puts others at risk.
"There is a gap in the current system," they say.
"If we're operating international [flights], we need to stick with international. If we're operating domestic, we need to stick with domestic."
Dr Johnston maintains that the risk is low.
"Yes, it is true that can happen. But the level of risk is very low."
But Baker says low risk doesn't mean there's no risk and mixing crews is a real concern.
"Again, poses a risk of infecting large numbers of people."
Air New Zealand says it doesn't make up the rules, the Ministry of Health does.
Newshub asked the ministry whether the current settings are strict enough. It says given the emergence of new variants, "we are constantly reviewing our processes".