Security Intelligence Service chief Rebecca Kitteridge has offered her condolences to the victims of the Christchurch mosque attacks.
Kitteridge and Government Communications Security Bureau head Andrew Hampton are appearing before Parliament's justice select committee this morning.
In her opening remarks, Kitteridge spoke about the attacks and offered her condolences.
The spy chiefs are appearing as part of the committee's inquiry into the 2017 New Zealand general election.
Such an inquiry is held after every general election.
Hampton said the committee had asked the pair to comment on potential foreign interference in elections, including the hacking of emails and the issue of foreign donations.
Hampton said they were limited in what they could say to be able to protect their sources. It was also a practise not to specifically name countries that may be involved.
Kitteridge said foreign interference did not refer to normal diplomatic relations.
She said foreign interference in elections was, and remained, plausible.
Most states had the ability to interfere in New Zealand elections.
They also did not have to be successful to be damaging to democracy.
The committee would be briefed on the potential to hack MPs' email and the use of traditional and social media.
Hampton said one of the main concerns during the last election was that hacked information could be used to influence the outcome. However, no activity of this kind was detected.
He registered the GCSB's ongoing concerns over local elections having online voting.
Cyber interference targeting voters had become one of the most common forms of interference.
To date, New Zealand had not been the target of widespread disinformation - but its occurrence overseas could have an impact here, Hampton said.
Kitteridge said the manipulation of expatriate populations by foreign states was also an issue.
Speaking about the issue of political donations, Kitteridge said the SIS became concerned about donations when their origin was unclear or obscured.
She said some activity was by state actors, which was concerning.
Kitteridge intended to write to all MPs offering advice on protective security around donations.
National MP Nick Smith asked Kitteridge and Hampton if they were satisfied they had all the legislative tools and resources they required to manage the risks.
Hampton said New Zealand legislation was fairly new and in some ways more enabling than some overseas legislation.
But he acknowledged that foreign interference was growing.