A 16-year-old boy has died and police are investigating whether he took an ecstasy tablet at Leeds Festival.
The teen fell ill during the music event on Saturday and was taken to hospital, but died on Sunday.
West Yorkshire Police said they are investigating whether he had ingested any type of MDMA.
Police said the boy’s parents have been informed and officers believe this was an isolated incident.
Assistant Chief Constable Catherine Hankinson said: “Our thoughts are with the family of the boy who passed away, and we have officers supporting them through this very difficult time.
“While the exact cause of death has yet to be determined, one line of inquiry is that he had ingested a certain type of ecstasy (MDMA) tablet, which was described as having a gray or black elongated shape.
“At this point, it is believed to be an isolated incident as we have not received any similar reports.
“Users of a drug that is not professionally prescribed can never be sure of the contents and risks of taking the substance.
“Anyone who feels ill after taking a substance should seek urgent medical attention.
“We will continue to investigate on site and maintain close contact with the event organizers.”
Anyone with information is asked to contact the police or local security, call 101 or visit the West Yorkshire Police website.