National leader Christopher Luxon says he's never seen under-fire MP Tim van de Molen be aggressive

National's leader says an MP accused of "threatening or intimidating" behaviour has never been aggressive in his presence. 

Newshub understands National's Tim van de Molen, the Waikato MP, is accused of standing over Labour's Shanan Halbert in a physically threatening manner, prompting other MPs to surround him at a meeting in late June. 

While National leader Christopher Luxon was limited on what he could say about the case, given it had been referred to Parliament's Privileges Committee, he told AM he'd never had a negative experience with van de Molen.

"Tim's a hard-working member of our caucus," Luxon said.

He said the facts of the case were "disputed", as highlighted by a statement from van de Molen on Tuesday.

Asked if he backed van de Molen, Luxon said, "Yes, I do".

"He's a hard-working member of our team, he's a great representative for the Waikato, he advocates very strongly for rural issues in particular and, as I said, the facts are disputed and it's before the Privileges Committee," Luxon told AM host Ryan Bridge.

"In terms of our caucus meetings, he can raise the issues that are going on for farmers and for the rural community… he's doing his job which is representing his constituency."

Luxon said van de Molen didn't raise his voice during caucus meetings.

He said the accusations against the MP were raised with him over the past few days.

"Under Parliamentary rules here, that just means none of us are able to comment or try and influence those proceedings, and that's why I won't talk further about it."

Parliament has had multiple ministers and MPs referred to its powerful Privileges Committee this year, something that's unprecedented in New Zealand's House of Representatives.

In June, it emerged now-former Transport Minister Michael Wood hadn't disclosed several conflicts of interest - including shares in Auckland Airport he'd been asked to sell multiple times by the Cabinet Office. That matter had since been referred to the Privileges Committee. 

Also in June, Education Minister Jan Tinetti was found not guilty of contempt for her delay to correct an inaccurate statement made in Parliament. She later apologised to the House. 

ACT MP Simon Court was also referred to the committee earlier this year and subsequently found to have committed a "clear breach" of confidentiality rules. That came after he revealed Select Committee information in a press release.