A 17-year-old girl has died of a suspected drugs overdose at Leeds Festival.
The teenager, who was from Oldham, died shortly after 03:40 BST at the Bramham Park Site, West Yorkshire Police said.
A 17-year-old boy, also from the Oldham area, has been arrested on suspicion of supplying controlled drugs and is in police custody.
Supt Matt Davison said: "Our thoughts are with the family of the girl who has died."
The Leeds Festival's police commander said the exact cause of the death was yet to be established, but it appeared the girl had "taken a combination of drugs".
Melvin Benn, from organisers Festival Republic, said: "To say we are deeply saddened about this tragedy is an understatement.
"West Yorkshire Police have taken action against those that may have supplied the drugs, and we will continue to work with them as usual.
"I would like to take this opportunity to remind anyone attending Reading and Leeds Festival that there is no safe way to take prohibited drugs and there are no safe prohibited drugs."
The Leeds Festival Police twitter account had tweeted a warning on Friday about some drugs on the site carrying "three times the normal average adult dose".
Please be aware of the following named substances Donkey— LeedsFestivalPolice (@LeedsFestPolice) August 23, 2019
Kong, Trump and Skype pills. They have been found in
circulation onsite. These are very dangerous, high strength pills, up to 3
times the normal average adult dose. pic.twitter.com/mLDnDO5JUI