Charlotte Dujardin, Britain's joint-most decorated female Olympian, has been provisionally suspended for six months by equestrian's governing body the FEI.
The dressage star had already pulled out of Paris 2024 after a video emerged which she said showed her "making an error of judgement".
The FEI said it had received footage showing Dujardin "engaging in conduct contrary to the principles of horse welfare - during a training session conducted at Ms Durjardin’s private stable".