The staff member at the centre of an incident involving former government minister Meka Whaitiri was left bruised in the encounter, the National Party has claimed in Parliament.
Speaking under the protection of parliamentary privilege, National MP Amy Adams said the allegations were at least of bullying and at worst assault.
Adams made the comments during a snap debate on Whaitiri in Parliament this afternoon.
"This involves allegations of at the very least bullying and at the worst violence and assault. If we are speaking about a minister laying hands on a staff member, that is incredibly serious," Adams said.
Adams said there had been no proper statement from the Prime Minister on what occurred, none from Whaitiri and no apology to the staff member.
"The public of New Zealand deserve to know if we have a minister of the Crown laying hands on a staff member to the extent that they end up with bruising."
Deputy Labour leader and Māori caucus member Kelvin Davis told Parliament the Māori caucus was sticking to its tikanga in its support of Whaitiri and did not have to answer to Adams for its actions.
"One of our tikanga is to stand up and support our people when they need our support," Davis said.
That did not mean they passed judgment or agreed or disagreed with what was done, he said.
"In Māoridom it's important to stand beside your people, it's important to be there, just to hold them up, just to help."
"That's a tikanga that we understand and we know, and we don't have to justify to any Member of Parliament from the Opposition who has absolutely no idea."
"She's standing there in judgment of us and quite frankly, as Māori we're sick of people like herself standing up and judging us for the way we do things.
"We don't have to justify our tikanga and the way we operate to anybody, least of all Amy Adams."
Comment is being sought from Whaitiri on National's allegations.
The details of the incident in Gisborne on August 27, between Whaitiri and a staff member who had been in her office only a week have not been made public.
But a report into the incident by Ministerial Services was enough for Prime Minister Jacinda Ardern to sack Whaitiri as a minister last week, saying she had lost confidence in her.
Whaitiri disputed some elements of the report but said today she accepted Ardern's decision.
Whaitiri said she was "absolutely gutted" by her sacking.
"I accept the Prime Minister's decision. I'm going to take the time now to reflect, and look at ways of improving myself to regain the Prime Minister's confidence," Whaitiri told reporters today.
Whaitiri and her Māori caucus co-chair Willie Jackson spoke to reporters on their way into Labour's caucus meeting today.
Jackson said Whaitiri "100 per cent" had the confidence of the Māori caucus.
"We had a meeting last night, and unanimous support for her," he said.
"The Māori caucus has taken into account the great work that she has done in terms of our strategies and going forward, so there's a heck of a lot of support there."
Whaitiri, who holds the Māori electorate of Ikaroa-Rāwhiti, said she had a lot of work to do on behalf of her constituents.
"I just want to get on with it," she said.
Jackson said there was no reason why Whaitiri could not be a "strong and good MP for Ikaroa-Rāwhiti and a leader for our caucus".
He would not say what discussions the Māori caucus had had with the Prime Minister's decision.
"The discussions with the Prime Minister remain private. We support her decision and we support our colleague continuing in a leadership position."