Officials warned Ardern that this was a problem all Five Eyes partners had experienced and all members take this problem "seriously," according to the top officials.
"All have detected a growing extreme right-wing phenomenon and have had instances of terrorism and lower-level violence."
In the report, officials warned Ardern: "Right-wing, Islamic and other extremists are using the Covid-19 crisis to spread hate, conspiracies and extremist narratives".
"Internationally this has included anti-Chinese racism, theories that the virus was deliberately started or spread by traditional enemies such as Jewish people or the "Deep State", and claims that the pandemic is less serious than stated and governments are using it to enforce authoritarian measures."
Although, at the time the report was written in May last year, New Zealand's terror threat was at medium, "periods of crisis open up the political space for extremists to fill with misinformation or to exacerbate people's fears of the other".
"This has been true of the Covid-19 pandemic, with those spending more time online in self-isolation at increased risk of exposure to extremist content and of radicalisation.
"This is of significant concern as right-wing extremists online have encouraged attacks against target communities, including deliberately spreading the virus."
The report cited a neo-Nazi bomb plot against a hospital treating Covid-19 patients in the US as evidence of this.
"Lockdowns may present challenges to would-be attackers but will not necessarily deter small-scale attacks."
But another report, also released under the OIA, detailed the risk profile of Islamist extremists in New Zealand.
"Risk Profile notes that New Zealand agencies are aware of a small number of Islamist extremists in New Zealand who were of security concern and who had the capability to commit an unsophisticated terrorist attack," the report said.
It added that there have been numerous calls of encouragement over many years from the Islamic State and al-Qai'da, and their support to conduct attacks targeting the West.
"Since the Christchurch terrorist attack, calls of encouragement have specifically mentioned New Zealand."