Since the event started on Friday 13 people have been arrested for offences including drug dealing and theft. A 17-year-old boy was arrested for trying to smuggle 200 tablets in a bag he was carrying into the Staffordshire event.
Supt Martin Brereton, leading the Staffordshire police operation, said overall “in the first 24 hours [we] have seen very little crime and have proven that our security and policing operation is working well”. He warned festival-goers that taking the powder or crystals would lead to nausea, vomiting, hypothermia and general agitation.
People who had consumed it at other events needed urgent medical attention, police said.
Organisers said the drugs were likely to be sold as MDMA and warned people to be vigilant and contact police if offered the substance. Jay Z is headlining at the Staffordshire and Essex festivals on consecutive nights. Emergency crews at Hylands Park, Chelmsford, said most people they had helped were suffering from blisters and dehydration.