Police in Jersey have confirmed a tablet found at a junior show jumping championship hit by a doping scandal was a fast-acting horse sedative.
Officers said no-one would be charged because no Jersey laws had been broken.
More than 30 ponies were due to take part in the British Showjumping Association's junior championships qualifying round on Saturday.
Members of the Association's Jersey branch alerted police after ponies became "unusually lethargic".
The under-16s event in St Lawrence was immediately cancelled for safety reasons.
One woman claimed she saw something drop from a pony's mouth and found an acetylpromazine (ACP) sedative tablet on the ground.
Following suspicions of foul play, blood tests were carried out on two ponies by analysts for the States of Jersey.
A police spokeswoman said: "The analysts confirmed that the tablet they found was ACP. They also took blood samples from two horses. They are being worked on and the results are expected next week."
ACP is a sedative used by vets to calm nervous horses for purposes such as clipping.
The British Show Jumping Association (BSJA) is expected to take a keen interest in the results of the blood tests.
An offence of bringing the sport into disrepute would, if proved, be punishable with a fine or suspension, the BSJA said.
The junior event has been rescheduled for later in the year.