A teenager has died and three other people are in a critical condition in hospital from suspected drug overdoses at a music festival in Sydney's inner west.
Police say the 19-year-old man died in Concord Hospital after attending Knockout Games of Destiny — billed as the biggest indoor festival in the southern hemisphere — at Sydney Olympic Park yesterday.
Two women, aged 19 and 25, and a man were taken to Westmead Hospital, where they remain in a critical but stable condition.
Thirteen other people were also taken to hospital for treatment.
Officers said an 18-year-old woman was allegedly found with almost 400 MDMA caps and was charged with supplying a prohibited drug.
Four other people were also charged with drug supply offences.
South West Metropolitan Region Commander Assistant Commissioner Peter Thurtell said many festival-goers were choosing to ignore warnings about illicit drugs.
"There is no acceptable use for drugs — the message is clear," he said.
"We will continue to have a strong presence at festivals and dance parties with the wellbeing and safety of attendees our number one priority."
Officers from Auburn Police Area Command are investigating the circumstances surrounding the man's death and a report will be prepared for the coroner.
NSW Police will address the media about the suspected drug overdoses at midday.
An 18-year-old man died at a Knockout music event last year, after he tripped over and fell on his head.