Knauß tested positive for the anabolic steroid Nandrolone at a World Cup downhill in Lake Louise in Canada on 27 November 2004 and was subsequently given an 18-month ban from sport.
The athlete Knauß was found to have used the banned substance Nandrolone during a World Cup downhill event in Lake Louise, Canada on 27 November 2004, resulting in an 18-month ban from participating in sports.