Updated 5:33pm: The privacy watchdog has asked MPs to rein in proposed spy powers in a new law change being rushed through Parliament.

Privacy Commissioner John Edwards is concerned about the scope of the proposals, for the SIS to carry out video surveillance and access travel data from Customs.

He's told a select committee hearing the law change gives extraordinary powers to one bureaucrat - the SIS director - to surveil citizens, and more oversight is needed.

Mr Edwards says the proposed 48-hour window for unwarranted video surveillance, and a 12-month lifespan of the warrants, should both be restricted further.

And he's expressed concerns about the SIS getting "unimpeded access" to Customs' passenger information, without a warrant.

"There is a possibility that New Zealand would be seen as an outlier in giving security service access unimpeded to information which the customs services itself would be required to obtain a warrant for."

Law Society voices concerns

Further checks and balances are being sought on the Government's proposed foreign fighters legislation.

The call's being made by the new Zealand law Society as it raises concerns about the Bill's impact on civil liberties and human rights, particularly around warrantless surveillance

Society President, Sir Geoffrey Palmer says New Zealand does have an obligation to follow United Nations Security council resolutions and legislate.

"There needs to be a little more attention to human rights and liberties here."

And he's also commented on the way the Government is fast-tracking the Bill into law before Christmas.

"Legislation that is rushed, where there is insufficient time to examine it's detail, often ends up missing it's target, or actually causing unexpected consequences."

Public submissions will be heard in open sessions over the next few days, before the legislation is passed under urgency.

Top spy backs law change urgency

MPs have received a lengthy, secret briefing from the country's top spook, on the need for anti-terror laws to be rushed through Parliament.

The country's top spy is backing a law being rushed through Parliament to crack down on foreign fighter suspects.

SIS director Rebecca Kitteridge gave evidence in a closed-door hearing, at Parliament's foreign affairs select committee this morning.

She briefly spoke to media after the hearing.

"If the Service had input into the policy, you can be sure that we think it is necessary. As people have seen the threat level in New Zealand has been raised, and the context in my view justifies these additional provisions."

New SIS surveillance powers 

A select committee has just begun its urgent hearings on the legislation, which includes new SIS surveillance powers, and the ability to cancel passports for longer, for foreign fighter suspects.

Rebecca Kitteridge was tight-lipped after the hearing.

"I was able to answer some questions that the committee had about some of the circumstances that we have in New Zealand, and to provide examples, so I'm not going to comment on any specifics of the legislation."