The two people who died after falling ill at Mutiny Festival have been named as an 18-year-old woman and a recent father.
Georgia Jones and 20-year-old Tommy Cowan were both named locally as those who died after being taken to hospital from the Portsmouth event on Saturday night.
They were among 15 revellers admitted to Queen Alexandra Hospital from Mutiny that night, with organisers issuing a warning of a "high strength or bad batch" of drugs.
The second day of the festival, which Craig David and Sean Paul were due to headline, was cancelled as a "safety precaution".
It is with tremendous sadness that we can confirm that two of our festival family died in hospital overnight.An 18...
A spokeswoman for the hospital said it was believed they were admitted after falling ill from the effects of drugs. Another person remains in a critical condition.
Mr Cowan, also known as Tommy Bakeer, was described as a caring young father.
According to Portsmouth local paper The News, his father, Damian Cowan, 43, said: "He was funny. He loved life and he loved his little boy.
"He was everything. He was a good lad - unfortunately he made a bad choice."
Mr Cowan was a "brilliant" friend, according to 19-year-old Jack Ford, who said they met at college studying uniformed services.
"He is such a caring guy who would do anything for any one. He loved going out with his mates but most importantly loved spending time with his girlfriend and son," said Mr Ford, who lives near Portsmouth.
"It was a big shock to lose such a great guy like him."
Both of those named as victims were from Havant, Hampshire.
Police said the woman was taken ill at the festival in King George V Playing Fields at 7.10pm before the man was found collapsed 20 minutes later.
A further 12 concertgoers went to the hospital on Saturday, but their cases were "not necessarily all drugs-related", the hospital spokeswoman said.
Three more attended on Sunday morning to be treated for injuries sustained in assaults or because of alcohol-related intoxication, the spokeswoman added.
Hampshire Constabulary is investigating but said the deaths were separate incidents and were not suspicious.
We can confirm that two people have died after falling ill at Mutiny Festival in Portsmouth.An 18-year-old woman and...
Mutiny warned at around 9.30pm on Saturday, after the pair were taken ill, that it was "aware of a dangerous high-strength or bad-batch substance on site", and that no drugs should be taken.
The festival announced the deaths, before adding: "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 organisers of the festival, which was headlined by Dizzee Rascal on Saturday, also urged customers to "responsibly dispose" of any substances.
Sean Paul paid his respects to the loved ones of the pair who died, as did Craig David, who tweeted: "My heart goes out to the family and friends of the two young people who lost their lives at @MutinyFestivals yesterday."
The force said next-of-kin for both the victims had been informed.
Anyone with information should contact police on 101.