London, Apr. 20: An Auckland airport worker has tested positive for Covid-19 a day after New Zealand opened a reciprocal travel bubble with Australia.

The case appears to be unrelated to the travel bubble though, and flights with Australia have not been suspended.

Thousands of passengers flew between the two nations on Monday for the first time in more than a year.

New Zealand PM Jacinda Ardern said the infected person had been cleaning planes from "high risk countries".

She told reporters that the worker had been fully vaccinated, adding that while the jab did not fully eliminate the risk of getting infected, it meant that positive cases "won't get sick and they won't die".

Ms Ardern said she had not yet spoken to her Australian counterpart Scott Morrison, but that she didn't expect the case to affect the travel arrangement between the two countries.

"When we opened, on both sides, we of course knew we would continue to have cases connected to our border... We accept that's going to be part of our journey together, I think Australia accepts that," she said.

The long-awaited travel bubble means visitors no longer needed to quarantine on arrival.

Jetstar is one the airlines that have resumed flights

Under the New Zealand government's guidelines for the bubble, the travel arrangement would only be paused if a Covid case came from an unknown source.

If there were multiple cases of an unknown source, triggering a regional lockdown in the affected area, the travel bubble would then be suspended.

Both New Zealand and Australia have contained Covid-19 outbreaks and have won praise for their handling of the pandemic.

Strict border controls and snap lockdowns are among the measures that have kept infection rates low.

Australia has recorded 910 deaths and New Zealand 26 deaths.

Both countries closed their borders in March 2020 and introduced quarantine for returning nationals.

Since October, travellers from New Zealand have been allowed to enter most Australian states without quarantine, though this had not been reciprocated amid concerns about sporadic Covid outbreaks in Australia.

To fly under the new bubble's rules, passengers must have spent 14 days before departure in either Australia or New Zealand.

They must not be awaiting the results of a Covid test, nor have any Covid symptoms, amongst other criteria.