AUCKLAND • The New Zealand authorities have sacked nine Customs workers over their refusal to be inoculated against Covid-19, including four from a single provincial port.

The dismissal was ostensibly because alternative roles could not be found for the workers and came as more trouble hit the New Zealand-Australia travel bubble overnight.

The New Zealand government had made it mandatory from April 20 for all workers in managed isolation and quarantine facilities, as well as personnel working for government agencies at the border, to be vaccinated under its Covid-19 Public Health Response (Vaccinations) Order.

One maritime border worker, requesting anonymity, told The New Zealand Herald she was devastated to be sacked. She alleged that she was fired due to a lack of consultation by the Customs agency.

Another worker, who was responsible for monitoring international ships to make sure the crew took appropriate Covid-19 precautions, said she believed there was insufficient risk in her role to justify being sacked over her refusal to be vaccinated. She did not disclose the reasons for her hesitance to be vaccinated.

The sacked workers are not being offered redundancy payments because their roles will be filled by others, the Customs agency said, while defending its communications with the workers.

Ms Catherine Stewart, an Auckland employment lawyer, said employers of workers required to be vaccinated were likely to be able to "substantively justify dismissing an unvaccinated employee".

New Zealand Customs people and capability deputy chief executive Jacinda Funnell said more than 95 per cent of Customs staff have been given their first vaccine jab and more than 85 per cent have received the second dose.

Meanwhile, an infected security guard at a Perth facility prompted the cancellation of flights between Western Australia and New Zealand on Saturday night. The New Zealand Ministry of Health announced shortly after 10pm on Saturday that it was decided after a rapid health assessment that flights from Western Australia to New Zealand should be paused.

The cancelled Air New Zealand and Singapore Airlines flights had been scheduled to fly from Perth to Auckland yesterday morning.

Two of the seven people sharing a home with the guard also tested positive.

Western Australia Premier Mark McGowan said the state would not go into lockdown at this point, though he stressed that this could change. "(Closed-circuit television footage) is being reviewed. However, there is no clear explanation at this point as to how the security guard could have been infected," Mr McGowan added.