Daniel Dung Huynh, 25, from Punchbowl, was arrested at Auburn Police Station on Friday morning and charged with two counts of supplying a prohibited drug.

He was refused bail in Burwood Local Court on Friday afternoon.

Ms Choi, a 25-year-old pharmacist from Oyster Bay in Sydney's south, reportedly drank MDMA dissolved in a water bottle before falling ill about 5.15pm. She was pronounced dead at Concord Hospital about 9pm.

A further ten people were taken to hospital following suspected drug overdoses, including a 22-year-old tourist from Britain who was placed in an induced coma.

Police charged more than 69 people with drug offences at Stereosonic and more than 120 people were treated for the effects of drugs, prompting police to warn that drug users are "playing Russian roulette with your life".

Staff working for the private medical company, Event Medical Services, and the event organisers, Totem Onelove, were told not to speak to the police after Ms Choi's death.

The security firm contracted by Totem Onelove are also investigating allegations that one of its guards took drugs during their shift at Stereosonic and had to be hospitalised.

Since Ms Choi's death, harm reduction advocates have renewed calls to allow drug checking services that would tell users the purity and composition of their pills and powders.

Ms Choi was the fifth person to die at a music festival in the last year.

After the death of 19-year-old Georgina Bartter at Harbourlife in 2014, two people were charged with drug offences including her best friend, Rebecca Hannibal.

The 25-year-old Punchbowl man charged with drug supply will appear in Burwood Local Court on Friday afternoon.