Victoria Police have had to cancel hundreds of speeding tickets and fines after a software virus was found in their systems.

All of Victoria's 280 red light and speed cameras will be reviewed after a total of 97 cameras were identified as having a virus.

The code was reportedly introduced to the system by a contractor during routine maintenance.

Police say they have withdrawn up to 8,000 fines issued between June 6 and June 22, and cancelled almost 600 speeding and red-light tickets.

The infection was allegedly the WannaCry virus, which was leaked by hackers earlier this year.

Police Minister Lisa Neville says the terms of reference for an inquiry into the matter have been established.

“I felt that it was absolutely critical for public confidence in our red light and speed camera system that all 280 of our cameras would be subject to an investigation,” she said.

“A full investigation of both where the virus may have gone, how it happened, of all the 280 cameras, how many had been infected and whether there's been an impact on the broader system.”

The Minister said the Police believed only the cameras controlled by the Windows operating system were infected, but its alternative Linux system now appears to have been affected too.

“What it means is that of the 280 cameras we have operating across Victoria, I need to be sure they were operating correctly, with integrity, without interruption,” Assistant Commissioner Doug Fryer said.

“We will embargo [the fines] until the review has been concluded. Moving forward, no tickets will be issued from this date until we get the response from the road safety commissioner.

“That does not mean that the 280 both fixed and red light cameras are not operating. They are.

“They will be catching people that are speeding. They will be catching people going through red lights.”

Three separate providers have contracts for the cameras.

Part of the road safety commissioner’s review of the matter will investigate how adequate the Department of Justice's oversight and governance of the contractors is.

The review should be completed within weeks.