The heads of New Zealand's intelligence agencies say there are active efforts to influence democracy here through expat communities and political donations.

Photo: AFP or licensors

SIS and and GCSB heads Rebecca Kitteridge and Andrew Hampton have briefed MPs about foreign interference in elections at select committee.

MPs are holding a general inquiry into recent general and local elections, and are considering foreign interference as part of that, a hot topic after stories around major events like the 2016 US Presidential election, and Brexit.

Prime Minister Jacinda Ardern, asked about the presence of any foreign spies in Parliament, said she couldn't rule it out as that would breach high level intelligence briefings.

Ms Kitteridge also refused to comment on what briefings had been given to ministers and the leader of the opposition.

Photo: RNZ / Jane Patterson

In a statement, National Party leader Simon Bridges said he did not disclose briefings he may or may not get on National Security but that he had full confidence in all his MPs.

Ms Kitteridge told media following today's select committee the SIS was aware of efforts by foreign states to "covertly monitor or obtain influence" over expatriate communities in New Zealand.

She said there had been concerning activities aimed at influencing domestic politics.

"What we do see is foreign interference activity in New Zealand from a range of actors, and that is through a range of vectors, including some concerns we've have about political donations being made by state actors where the origin of those donations has been unclear,'' she said.

Neither Ms Kitteridge nor Mr Hampton would name specific countries.

Justice Minister Andrew Little said Parliament always needed to be alert to the possibility and risk of foreign interference, and was open to changing the law - include re-assessing whether New Zealand needed foreign donations - depending on the findings of the inquiry.

"I think most MPs and candidates know that a risk during campaigning is that they come under the influence of others. It's something in the political realm that you're constantly alert to.''

Photo: RNZ / Rebekah Parsons-King

He said that precise risk was one of the reasons the justice select committee was doing its inquiry into the 2017 election - to make sure the country's donation laws were "robust enough''.

Ms Ardern reiterated that New Zealand was "not immune" to interference. She said it was important to make sure the country's laws were "agile" and "fit for purpose" when it comes to political donations and foreign interference.

"One thing we've done since we've been in government is have the Justice Minister write directly to the justice select committee to say 'please look at the issue of foreign interference in the 2017 election', including of course the issue of donations.

Photo: RNZ / Rebekah Parsons-King

"What I'm hoping is we'll generate some real consensus across Parliament on whether any law change needs to be made and what that might look like,'' she said.

New Zealand First leader Winston Peters said there were good laws are in place to avoid undue influence, but foreign countries trying to influence other political systems is nothing new.

"There are countries, and I don't want to name who they are, but some are - you might say - rather too connected with the political system locally in their own interests," he said.

Mr Peters said a foreign company had once offered him enough money "to make your head boggle" in return for special treatment.

Photo: RNZ / Rebekah Parsons-King

However, he said there was no need to change the laws governing donations to political parties, as the current rules were sufficent.

Donations over $1500 must be declared and parties are not allowed to keep overseas donations or contributions of more than $1500.

"Let's not throw out everything that's good just because a few people are what I would call electorally crooks," he said.

National's Nick Smith said National would support scrapping foreign donations.

"We firstly need to ban foreign donations. This is our democracy, we shouldn't have foreign governments or parties trying to influence it. A more challenging part is then setting up the regulatory system to ensure it occurs,'' he said.