The Search and Surveillance Bill 2009 gave rise to "significant privacy issues".
"It does cover activities that are intrinsically invasive. One just can't get away from that."
She said people's confidence their telecommunications were secure from intrusion "is an essential feature of private life and the ability to communicate freely".
The new law will bring together under one regime surveillance device warrants for audio, visual and tracking surveillance.
Interception devices are at present used in investigations of serious crime.
Their use is prescribed in various Acts such as the Crimes Act and the Misuse of Drugs Amendment Act, but there are few controls over visual surveillance.
The Bill increases the situations in which interceptions and tracking devices could be used.
"Instead of being restricted to certain types of serious crime, enforcement officers will be able to apply for surveillance device warrants on the same basis as search warrants," Mrs Shroff's submission said.
"You have got to balance that law-enforcement need to make sure we can pursue the really nasty people with a genuine public interest in privacy and making sure we strike that right balance," she told the justice and electoral committee.
She said she was generally supportive of the Bill, which is the result of an extensive review and report by the Law Commission.
It is supported by National and Labour as a means to tackle the growing sophistication of criminals and technology.
Mrs Shroff said it needed changes, and not just in a minor way, to address privacy concerns.
She wants the section on computers tightened to avoid enforcement agencies going on "trawling exercises".
The agencies should be required to state the nature of the material they were looking for.
She said the production orders at present - requiring people to produce information - were limited to specified serious offences.
Under the Bill, production and monitoring orders would cover those functions for any offence for which a search warrant may be obtained.
"This is a significant change in the law and will dramatically increase the availability of production and monitoring orders.
"These orders potentially make a vast amount of information available to enforcement officers."
She was concerned an enforcement agency could apply for a person's "call-related information", which could encompass phone calls, SMS messages, emails, texting and other forms of electronic activity.
She wanted any application for a production order to specify what type of telecommunication was to be covered.
Mrs Shroff was also concerned that the person issuing production orders could be someone other than a judge.
"Traditional expectations are that intrusions will not be made in private communications without rigorous oversight by a judge."
That was maintained in the Bill for the issuing of surveillance device warrants but not production orders, and it should be, she argued.
Green MP Keith Locke said one of the most worrying aspects of the Bill was the extension of surveillance to mean almost anything.
The provision for a "residual warrant for surveillance" meant any type of surveillance not already specified, which covered intrusion into the reasonable expectation of a person's privacy.
