Emergency services are seeking to expand their ability to locate at-risk people through their phones and other devices.
Currently, people can only be searched for if they make a 111 call but the change will allow anyone in harm's way to be tracked.
Privacy Commissioner John Edwards, who's charged with making the change, said he supported it as long as it was regulated.
"There is potential for misuse, so we have put very strict rules around it," he said, adding that it would likely come into force in April.
Edwards said it would save lives and reduce costs by helping emergency services locate missing people including those suffering from dementia.
"However, unregulated, the proposed changes could enable the locating of almost any individual in the country at any time. While this is neither our intention nor the intention of the agencies permitted to use the system, the technology required to deliver the extended system could be intrusive if misused," Edwards said.
The extensions would allow the active collection and sharing of the location of any device in the possession of a person at risk for example, a person lost in a national park, kidnapped, or having indicated an intention to harm themselves or others.
"I have sought to facilitate better public safety outcomes in a way that is proportional and does not open the door to abuses," Edwards said.
"We have proposed a set of new limitations and obligations, which build on the boundaries already in place, designed to protect against scope creep and ensure some accountability for the way the new system is used. I will review the system from time to time to ensure it is not being misused."
He is calling for public submissions on the proposed change which can be sent to privacy.code@privacy.org.nz before 28 February 2020.