Christchurch terror attack: Royal Commission Inquiry into intelligence services will be 'brutal' - terrorism expert

A terrorism expert and former SAS soldier believes a Royal Commission of Inquiry into New Zealand's security and intelligence agencies will be "brutal" in the wake of the Christchurch attacks.

On Monday, Prime Minister Jacinda Ardern announced the actions of the Government Communications Security Bureau (GCSB) and the New Zealand Security Intelligence Service (SIS) leading up to the March 15 shooting would be investigated.

Ardern said there were legitimate questions about how the massacre was able to happen, including why the alleged gunman was not on any security watchlist.

Chris Kumeroa, a former soldier who specialises in counter-terrorism with Global Risk Consulting, told Newshub the inquiry was necessary and shouldn't hold back in finding answers.

"It'll help to seem to understand the current state and [the intelligence services'] effectiveness, and then obviously there is a measuring tool around whether or not they have been capable," he said.

"I guess it will be fairly brutal and I guess there will be some serious questions that will need to be answered."

Questions are already being raised about whether the intelligence agencies were looking in the wrong place for terror risks, with a report released by the Human Rights Foundation finding Muslims felt unfairly targeted.

"This is a community that has felt under a lot of pressure - they've felt like they have been under unwarranted levels of scrutiny," Deborah Manning, a lawyer and executive member of the Human Rights Foundation, said.

Kumeroa said the focus of the intelligence services would need to be considered.

"What is necessarily our priority, actors or threats that we need to be conscious of, and then if you are not following their respective budgets to allow the agencies to do their job."

Security expert Paul Buchanan said the inquiry could take months, but he is pleased by what he has seen so far.

"There appears to be good faith on part of the agencies involved and I will give credit to Andrew Little because he seems to be cracking the whip on these people to the point that both the directors of the SIS and the GCSB have come up and fessed up that they didn't see this guy," he told The AM Show.

Buchanan also said the inquiry needs to look into what threats the intelligence services were focussing on.

"At the policy level, I think too much emphasis… was given to trying to detect and prevent home-grown jihadists," he said.

"[Intelligence services] have infiltrated animal rights groups, environmentalists groups, Maori sovereignty groups, leftie groups… quite frankly I don't think any of those groups constitute the threat that white supremacists do.

"It could be that they did try to infiltrate white supremacist groups, that they did have informants, but if these informants were in right-wing resistance, national front, these neo-Nazi groups, and the killer was not involved in these groups… even if they infiltrated the groups, they wouldn't have detected him."

The National Party supports the Royal Commission of Inquiry.

"We need to understand whether this could have been prevented," he said. "It will need to ask hard questions about whether our security and intelligence agencies had their focus in the right places," said leader Simon Bridges.