A distracted driver was filmed by fellow motorists as he watched a football match on his phone.
The suspect was seen swerving between lanes in an erratic manner as he approached a red light.
When the car stopped, the drivers behind were able to zoom in on the source of distraction, revealing a Juventus game playing on his mobile.
The suspect appeared to have his phone in his lap before replacing it in a holder attached to the windscreen.
The footage was released by Norfolk Police as part of “Operation Ringtone”, a crack-down on motorists using their phones at the wheel which launches this week.
It will see officers patrolling the roads with marked and unmarked cars and motorcycles, all fitted with cameras to obtain evidence to secure prosecutions.
Chief Inspector Kris Barnard, head of the Norfolk and Suffolk Roads Policing Unit, said: “We all witness it, momentary glances looking down at a phone or the more blatant offender seen holding and talking on their phone.
“The key thing to remember here is that while you’re behind the wheel you are in charge of a machine, a machine which can seriously injure and even kill people if you’re not in proper control.
“If you take your eyes off the road for just three seconds when doing 70mph you will travel further than the length of a football pitch. Ask yourself, what could happen in that time?”
A new reporting form on the police website means members of the public can now submit dashcam footage if they suspect wrong-doing.