Prime Minister Jacinda Ardern is unable to say if the latest border-related case of COVID-19 has been vaccinated.
The latest infection - known as case C - was reported on Sunday. They tested positive for COVID after contact with case B.
Both are workers at Auckland's Grand Millennium managed isolation facility and pose a low risk to the community due to both being in isolation, officials say.
The Ministry of Health is yet to say whether case C is vaccinated. The ministry revealed last week case B hadn't had the jab because they missed two scheduled vaccination appointments due to "personal reasons" - but gave no further explanation.
Ardern told The AM Show further details about case C would be released on Monday.
"So far, that's not something that I have all of the full details around - so I'm going to let [the Ministry of] Health put that out," she told host Duncan Garner, when asked if the case had been vaccinated.
Ardern reiterated being vaccinated for COVID-19 doesn't necessarily prevent infection.
"What it means is, for Pfizer [vaccine], you're 95 percent less likely to have [a] symptomatic infection - so you won't get sick."
She said the deadline is nearing for managed isolation and quarantine workers to get the jab - the end of April - or people risk being moved on to other jobs.
Ministry of Health officials say 90 percent of border workers have been vaccinated but are unable to say how many border workers there are due to its "continuous" recruitment process.
Director-General of Health Ashley Bloomfield will provide further details on the latest case at 1pm.