VicRoads has same power as the Police to stop any vehicle and issue any type of Traffic infringement, although they mainly focus on commercial vehicles.
If you fail to stop after being signalled to by a VicRoads officer, you can and will be charged for failing to stop. The offence is the same offence as failing to stop for the police.
People are often shocked to find out that VicRoads officer can issue Traffic infringements to ordinary people and vehicles, but it happens all the time.
Also they can and will defect your vehicle if they find something wrong with it, and they know a lot about vehicle standards.
