LONDON (AP) — A racehorse owned by Britain’s Queen Elizabeth II has been stripped of a second-place finish in this year’s prestigious Gold Cup after testing positive for the banned painkiller morphine.

The source of the positive test given by Estimate has been traced back to contaminated feed, and the horse’s trainer Michael Stoute did not face a penalty. The British Horseracing Authority was satisfied that all reasonable precautions had been taken to avoid any breach of the rules.

However, the racing rules state that horses producing a positive sample for a prohibited substance should be disqualified from relevant races.

Estimate, which won the 2013 Gold Cup, finished second in this year’s race in June behind Leading Light.

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