German dressage rider Isabell Werth has been suspended from competition after her horse Whisper tested positive for a banned substance.

Small tour horse Whisper tested positive for Fluphenazine at CDI Wiesbaden in Germany on 30 May.

Ms Werth — who has won five Olympic gold medals — has been suspended immediately.

She will not be allowed to compete at CHIO Aachen, Germany (26 June- 5 July).

Prohibited substance Fluphenazine is a sedative that is usually prescribed as an antipsychotic in humans to treat schizophrenia and bipolar disorder.

Breido Graf zu Rantzau, president of the German Equestrian Federation, said in a statement: “This is a catastrophe for the horse sport. But we don’t let ourselves be discouraged by all this negative news as we pave the way to a fair horse sport.”

A tribunal hearing has been scheduled for tomorrow (25 June) by the International Equestrian Federation (FEI) to decide whether suspension will be temporary or not.

Ms Werth has requested a B sample be tested.

Less than a month ago (28 May) the German equestrian team was disbanded and show jumper Ludger Beerbaum was suspended after doping allegations.