The agency can deploy the Israeli spyware Cellebrite, a phone-hacking technology, when investigating cases such as fraud and identity crimes.

Appearing at Senate estimates on Wednesday, agency officials took a number of questions about the technology on notice, including the criteria for its use, the number of warrants it had sought to use the technology as well as how metadata is stored and who can access it.

Services Australia also revealed it was able to offer the technology to other agencies, including the National Disability Insurance Agency and the Department of Education.

"It's one of the technologies and suite of capabilities we use to undertake investigations and they are of the higher end so by serious non-compliance, what we mean by that, is an investigation that's commencing as a criminal investigation," Services Australia deputy chief executive officer Chris Birrer told senators.

"Sometimes they don't meet sort of the standards for us to then refer a brief of evidence to the Commonwealth Director of Public Prosecution for them to consider, and that's why we use the term serious non compliance."

Senator Rice said: "I think that they are using it because they think it will be useful, but the potential of serious overreach is really real. It is really powerful spyware, Israeli spyware.

"The potential for that really impacting on people's right to privacy is massive.

"And yet, they were just so uncertain about some basic issues that I would have thought should have been in place in terms of how they use it, when they use it, who has to sign off to use it."

We've made it a whole lot easier for you to have your say. Our new comment platform requires only one log-in to access articles and to join the discussion on The Canberra Times website. Find out how to register so you can enjoy civil, friendly and engaging discussions. See our moderation policy here.