WATCH: Man Tumbles Out Of WA Police Paddy Wagon
Drivers were stunned to see a man roll out of a police wagon and on to a busy Perth road.
Dashcam footage shows the person tumbling onto the road as the WA police van turned into Newcastle St in the suburb of Northbridge.
The footage was posted on the Facebook page Dash Cam Owners Australia on Monday.
"It's clearly very disturbing ... there will need to be an investigation," Police Minister Michelle Roberts told reporters.
"It's obviously very important that prisoners are properly secured and kept safe.
"I don't know whether there's any failure in terms of locking the van procedure or whether there's a mechanical fault."