Security Intelligence Service head Rebecca Kitteridge says the higher threat level in New Zealand justifies proposed changes to terrorism laws.
Ms Kitteridge appeared in front of a parliamentary select committee that is hearing submissions today on legislation aimed at protecting New Zealand from the threat of foreign fighters.
The hearing comes amid accusations that the new laws are being rushed through Parliament.
The Countering Terrorist Fighters Legislation Bill, which passed its first reading on Tuesday, would extend the period for which the Government can cancel a passport from 12 months to three years.
It would also allow the SIS to carry out greater surveillance than it does now - including, in special cases, without a warrant for up to 48 hours.
Ms Kitteridge was the first to address today's committee meeting. She briefed the committee in private and, on her way out, told reporters that the legislation was necessary.
"[The] threat level in New Zealand has raised and the context really, in my view, justifies these additional provisions - but I'm not going to go into any more discussion about the merits of the legislation because it's in a political process now, and that's the process that it needs to be."
However, former Labour Prime Minister Sir Geoffrey Palmer warned MPs legislation often went wrong if it was rushed.
On behalf of the Law Society, Sir Geoffrey told the committee MPs needed more time to consider the bill.
"Legislation that is rushed, where there is insufficient time to consider its detail, often ends up missing its target or actually causing unexpected consequences," he said.
The proposed laws substantially interfered with, and reduced, human rights and individual liberties.
The committee, which is hearing submissions under urgency, will report back to Parliament next Tuesday.
The Government wants the bill passed before the House rises for Christmas on 11 December.
'Quickly emerging problem'
Critics have said the changes are too great to be rushed through so quickly.
But Chris Finlayson - the Attorney-General and Minister in Charge of the SIS - told Morning Report the measures were to tackle a fast-moving situation.
"This is an interim bill to deal with the quickly emerging problem of foreign terrorist fighters.
"We're basically doing what the UN Security Council Resolution 2178 asked all member countries to do - take steps to stop people leaving our shores and going and fighting.
"The full review of all security legislation will be held next year ... People will have an opportunity to make submissions on every piece of legislation."
Process 'farcical' - Labour
Labour's foreign affairs spokesperson David Shearer said it was a ridiculously short hearing, which the party only found out about yesterday.
"When we sat down in the select committee we found out some of the people and the organisations that we wanted to appear before us only had one day's notice."
He said he wanted to hear submissions from experts like the Law Society and people who would be affected, like the Muslim community.
"We knew it was going to be truncated but I think the degree to which it was being truncated has made it farcical," he told Morning Report.
"But more importantly than that, the Government I don't believe has made the case for why this legislation needs to go through in the haste that it is at the moment."
Mr Shearer said Australia was taking two to three months over changing its anti-terror legislation and the UK was allowing until May next year to hear evidence, but the New Zealand Government had not provided a rationale for the speed of its law change.
A terrorism expert said this country's legislation would negatively effect some students and teachers.
National Centre for Peace and Conflict Studies Deputy Director Richard Jackson said Muslims worried about their communities overseas might use jihadi websites for research.
"Well, you are now really at risk of being put under suspicion for becoming a terrorist yourself. This has a chilling effect. It restricts their rights and their freedoms to study what they want."
Federation of Islamic Associations president Anwar Ghani said the Government had every right to protect New Zealanders, and their political and economic interests, but the bill risked stigmatising Islamic people.
"It will further stigmatise our community and create a tension which we do not want to see."
As well, there was not enough time allowed for public submissions on it, he said.