Police are searching for a hoon who has posted two videos on YouTube showing a person riding a motorbike at speeds of up to 230km/h on Canberra roads.
Both videos, posted on YouTube in the past 10 days, are set to music and show the motorbike's speedometer as it drives dangerously throughout Canberra.
The biker who does not show him or herself on camera dangerously overtakes cars, buses and trucks in both videos.
The bike is shown speeding at more than 230km/h on the Monaro Highway and at more than 200km/h on Anzac Parade and 180km/h on Commonwealth Avenue.
The rider also appears to do a wheelie at high speed on Wentworth Avenue in Kingston.
Both videos appear to be shot in the inner south, including Kingston and Fyshwick. The videos had more than 700 views by yesterday afternoon. One video had received a three-star rating by users with the second video given five stars.
ACT Policing's traffic operations Superintendent Mark Colbran said the biker's actions were the worst he'd seen on video in his career. ''I've been a policeman for 25 years and I've seen some people do some pretty stupid things, but I've never seen such idiocy in a video in my life,'' Superintendent Colbran said.
He said police had been aware of the videos for ''a couple of days'' and they were trying to track down the person responsible.
Superintendent Colbran said the actions of the rider had the potential to cause carnage on the road.
He said the danger ''could be measured in milliseconds, one mistake, one pedestrian stepping across the road, or one car changing lanes, one car turning or merging and we would have had a multiple fatality and a terrible tragedy in Canberra''.
The person identified on YouTube as jmm006 signs off both videos with a promise of ''more videos coming soon''.
Superintendent Colbran said he hoped police could track down the offender or offenders before they had time to make another video.
''ACT Policing won't tolerate that behaviour and neither should any Canberra citizen,'' Superintendent Colbran said.
''We'll be prosecuting to the full extent of the law if we can identify the defender.''