The man responsible for building Australia's coronavirus tracing app has defended the technology, which has so far cost almost $1 million for each case identified.
Randall Brugeaud from the Digital Transformation Agency flatly rejected suggestions the COVIDSafe app was not working.
"The app is absolutely working," he told a Senate estimates hearing on Thursday.
"There is no question as to whether the app is capturing close contacts and contributing to the public health effort."
More than seven million Australians have downloaded and registered for the app, which cost $4 million to develop.
Another $5.2 million has been spent on operational costs and almost $7 million on advertising, taking the total price tag to roughly $16 million.
The app has only helped find 17 contacts not found by manual tracers.
Mr Brugeaud said the problem was not with the technology.
"The numbers that we get are the numbers that are reported by the states and territories," he said.
"The states and territories are the owners of the health-related information, so all of the contact information. The Department of Health federally owns the business side of the app."
Everyone identified through the app has been in NSW.
Mr Brugeaud said hundreds more cases that would not otherwise have been found were uncovered as a result.
The app has been updated 13 times since it was launched in late April.
Mr Brugeaud said security was always front of mind.
"As vulnerabilities emerge we progressively release improvements to the app," he said.
"Now, if new vulnerabilities emerge that are high risk, then we will accelerate the implementation of those changes."
The DTA is not considering integrating QR codes into the app.
Mr Brugeaud said it would be technically simple but would breach legislation controlling use of the app by capturing location information.
"We are prevented from knowing where people are and having that level of granularity," he said.
Australian Associated Press