All were admitted to hospital as a result of incidents at the Mutiny Festival in Portsmouth. Among the 15, a woman, 18, and a man, 20, were confirmed dead by police this morning,
Another person is currently in a critical condition.
A spokeswoman from Portsmouth Hospitals said: “We had 15 people come to the hospital which we thing were related to Mutiny Festival.
“Two of them have sadly died and we have another in a critical condition, as well as another who remains in hospital.
“Everyone else was in a minor condition.”
Queen Alexandra Hospital, where the festival-goers were taken, said that not all of the patients were admitted for drug-related issues.
The spokeswoman said: ‘It’s difficult to say how many were actually drug-related. ‘For example, this morning we had three more people come in but those were in relation to assault or intoxication.’
The annual event attracts thousands to the south coast of England every year.
Posting on the Mutiny Facebook page, a statement from the organisers said: “Following the terrible news from earlier today, the team behind Mutiny Festival are incredibly sad to announce that the Sunday of the festival has been cancelled as a safety precaution.
“The safety of our amazing customers has always been paramount to us and so to keep everyone safe and in respect to those who have passed, we have taken the decision not to open today.
“As you can imagine, this decision was not taken lightly and was taken with the support of the local statutory authorities who we continue to work with.
“Enquiries are being made into the circumstances of what has happened, but we must reiterate our advice to all our customers to responsibly dispose of any substances.
“More information will follow when available, we appreciate your understanding at this difficult time.”
Parts of this article first featured on our sister site Portsmouth News.