Scott Morrison insists his government's widely criticised coronavirus tracing app is working as designed.
The prime minister says COVIDSafe has been involved in tracing more than 300 cases in Victoria.
"It's supposed to work in combination with the physical tracing that is done by contact officer. The two go together," he told Triple M Melbourne on Wednesday.
"Technically, it's working fine."
While the app has been involved in tracing infections, it has not identified any unknown close contacts.
"It's doing its job but it was never supposed to be in isolation to replace physical tracing," Mr Morrison said.
"The physical tracing is quickly identifying a lot of the contacts."
The Victorian chief health officer confirmed COVIDSafe had not detected any close contacts in his state that weren't already identified through manual processes.
"The app has not added a close contact that we haven't found through our very extensive long-form interview that takes an hour or more," Brett Sutton told reporters in Melbourne.
Labor has described the $2 million app as an expensive dud, with government senator Matt Canavan also conceding the technology had not been as successful as first hoped.
The prime minister said: "People taking pot shots at it, I think, are just undermining confidence and that's not a good thing."
"It's a good thing to get people to download the app and not be throwing stones."
Australian Associated Press