Prime Minister Jacinda Ardern is defending New Zealand's transparency when it comes to party donations and says the country is free from foreign interference.

Photo: RNZ / Dan Cook

Ms Ardern also confirmed the Chinese businessman behind the alleged $100,000 donation to National attended a Labour fundraiser in 2017.

It's been revealed that in a phone conversation National's leader, Simon Bridges, and MP Jami-Lee Ross discussed a relation of a wealthy Zhang Yikun going through candidacy school.

The businessman has been at the centre of claims of a $100,000 donation to the party, which Mr Ross alleged was "split-up" illegally.

Mr Bridges denies the claim, and Mr Ross has failed to produce strong evidence to back his story.

Ms Ardern told Morning Report Mr Zhang attended a Labour fundraiser on September 9 2017 but she does not know if he donated any money.

"We've complied with the law. He's not on our declaration.

"There's no register of a donation from him," she said.

Ms Ardern said she met Mr Zhang "in passing" but had not discussed donations with him.

On Friday, University of Canterbury professor Anne-Marie Brady told Morning Report politicians needed to look deeper into the connections of donors.

"The real threat that I'm paying attention to in this story is the failure of our political parties to prevent foreign government interference into our democratic political processes.

"The matters we need to look into is the connection of some of these donors, not all of them... to the Chinese party state. The Chinese Communist Party is an elite party and they have a tactic, which was set by Lenin ... and it's called the United Front. It's a way to influence non-party members and in the case of foreign policy, foreigners."

Professor Brady said New Zealand politicians should be wary of the intentions behind any donations.

"It seems that they think that they can take this money and then maintain independent foreign policy and independent New Zealand domestic politics, but it's very clear that the money comes with strings attached and that was revealed in that conversation that Jami-Lee Ross played to us all this week.

"One of the things we need to do in New Zealand is to start to see China the way it really is.

"We need to upskill our local politicians and our national politicians in our public sector. In the 'abc' of the Chinese party state, we've got to be able to engage with China and understand it, but also recognise the risks."

However, Ms Ardern said New Zealand has a "pretty good" suite of measures when it comes to foreign donations, and anonymous donations can be very small amounts.

"We're ranked number one in the world for transparency. We operate in a way that demonstrates that we are free from political interference," she said.

She said it would be preferable to have a political system where parties did not need to raise their own money.

"It would be a much easier political environment if we didn't have campaign fundraising," she said.