"Just want to let my people in Germany know I won't be on Wetten Dass tonight as an accident has taken place and ... we all don't think it is right to continue. Please pray for Samuel Koch & his family as we wait and hope for his health and safety," News.com.au quoted Bieber as tweeting.
The popular, family-orientated show features people performing unlikely feats, while celebrity panelists predict whether they will succeed or not. Koch, 23, who was wearing a chest protector, knee pads and a helmet at the time of the accident, had four minutes to somersault over five cars while wearing so-called kangaroo boots or powerbocks.
Koch, a German student and gymnast according to one blogger, succeeded at his first jump, baulked at his second jump, and landed on his face as he lost his balance after jumping over the third car driven by his father Christopher.
Presenter Thomas Gottschalk announced he was calling off the show for the first time since he had began hosting it in 1987. He said Koch was conscious and was taken to the University Hospital of Dusseldorf. The incident was broadcast live to millions of viewers in Germany, Austria and Switzerland on Saturday night and was later posted to YouTube for the rest of the world to view.