New Zealand minister sacked after 'physical altercation'

A government minister who allegedly had a physical altercation with a press secretary was fired by New Zealand premier Jacinda Ardern on Thursday, the second to leave under a cloud in as many weeks.

The centre-left prime minister did not detail what Customs Minister Meka Whaitiri did during an incident last month, but said an internal government report into the matter convinced her the minister needed to go.

"Based on the context and conclusions of the report, I no longer have confidence in Meka Whaitiri as a minister at this time," she said.

Unconfirmed media reports said Whaitiri was accused of bullying after becoming involved in a physical altercation with a press secretary who had just started working for her.

Ardern, who swept to power on a wave of "Jacinda-mania" late last year, denied Whaitiri's demotion was a sign her coalition government was becoming unstable.

It comes after Ardern's former broadcasting minister Clare Curran resigned earlier this month for using a private email account to conduct government business.

Both casualties will stay on in parliament, meaning Ardern's coalition government retains its three-seat margin.

But their demotion reinforces perceptions that the charmed run that marked Ardern's early months in office has come to an end.

"Of course no one wants to lose ministers," she told reporters.

"But I have to make decisions based on the information I have in front of me and I've made a decision, Meka no longer has my confidence." Asked if her government remained stable after two rapid-fire departures, she replied: "Absolutely."