Vo Dang Khoa Phan, 22, pleaded guilty of delivering drugs to Defqon. 1, a music festival near West Sydney, at a trial on Tuesday.
The U.K.-based news website Daily Telegraph reported that Phan has been granted bail and will be back in court for sentencing on November 16.
Phan was one of 10 partygoers charged with “drug supply offences” at the music festival where 23-year-old man Joseph Pham and a 21-year-old woman Diana Nguyen died after collapsing of suspected drug overdose on September 15.
Following a crackdown, Khoa was caught with the gamma hydroxybutyrate drug worth $1,000 hidden in 20 soysauce bottles.
Drug overdose has become a threat at music festivals around the world.
Just two days after Defqon. 1., seven people died at the Vietnam Electronic Weekend festival in Hanoi, and several others were hospitalized in critical condition. Director of the company organizing the event and a suspected drug supplier have been held for investigation.