He made a decision to cancel the fines in the interest of community confidence in the camera system, he said.
He understood the virus tried to connect to the internet to encrypt the system - but the cameras are not linked to the web.
The infection was detected after police monitoring the cameras noticed that they were rebooting more frequently than normal. He said the majority had been fixed, with "dozen or so" still infected.
Commission John Voyage said it was likely a camera tester had breached protocols by inserting an infected USB into the individual computers of the cameras earlier this month.
'It's important that we give the public some confidence around our camera system in Victoria.More news: Jared Kushner arrives in Middle East for meetings with Netanyahu, Abbas
Victoria Police have cancelled fines issued using evidence from speed and red-light cameras infected by the WannaCry ransomware.
"Our advice at this stage is that a software virus has been detected, however the camera system has not been compromised", police said in a statement.
A Department of Justice and Regulation spokesman said 55 intersection and highway cameras were impacted by the virus which was mistakenly introduced by a contractor.
It is understood that the infection came as a result of "human error" rather than a targeted attack aimed at holding the Australian state to ransom. "The remaining sites will be rectified in the next couple of days".
An inquiry into the incident will be launched on Monday, and meetings will be held with the state's sheriff, traffic camera commissioner, and the assistant police commissioner of road policing.
A system patch to prevent the virus from spreading further has been applied to the network of cameras. "All cameras have been operating correctly and accurately during this period".