Police in Jersey are investigating allegations that ponies at a children's showjumping contest were drugged.
Officers were called after competitors at the contest in St Lawrence complained animals were lethargic.
More than 30 ponies were due to take part in the British Showjumping Association's junior championships qualifying round on Saturday.
It was then cancelled for the safety of the animals and their riders. Animal blood samples are being analysed.
It is alleged a parent fed a fast-acting sedative to rivals' horses after being seen giving "mints" to a number of ponies.
The owner of two of the animals claimed to have seen something fall from one horse's mouth and found an acetylpromazine sedative tablet on the ground.
The drug is used to calm nervous horses for purposes such as clipping.
Insp Richard Bree of Jersey Police confirmed the force was investigating that "someone believed their pony had been doped in some way, shape or form".
He said: "The event was cancelled because they were concerned about the animals.
"The chief vet for the island has taken samples of blood from the ponies and inquires are ongoing.
"We are still awaiting the results of the blood tests."
Island British Showjumping Association branch chairwoman Penny Crutwell said: "We had a few ponies that were not acting in their normal manner.
"If horses are jumping under sedation of any description it can hinder their performance and there could be an accident.
"It was the final of the Under-16 Show Jumper of the Year and they were competing at quite a high level."
One pony was so unsteady it needed assistance to be loaded into a trailer so it could be taken home.
Ms Crutwell said senior classes in the championship had gone ahead as planned and the junior competition had been rescheduled for later in the year.