The New Zealander who died at the Nevada Burning Man festival had a poisonous amount of carbon monoxide in his body.
According to the Pershing County Sheriff's Office, Shane Billingham was pronounced dead at the desert festival's medical centre on Thursday (local time).
The Reno Gazette-Journal reports that toxicology results showed a poisonous concentration of carbon monoxide in his blood. The Sheriff's Office previously deemed the death suspicious.
A spokesperson for the festival said the Kiwi was found unresponsive in his vehicle on Thursday night and other festival attendees had performed CPR before emergency responders arrived.
The Ministry of Foreign Affairs and Trade told Newshub that the New Zealand Consulate-General in Los Angeles is providing consular assistance to Billingham's family, however, due to privacy considerations, no further details would be released.
A makeshift memorial has been set up at the festival for the Kiwi, with the Journal describing it is an altar covered in floral black silk.
Billingham's Facebook page shows him posting about the event earlier this month, asking who else was going.
Many of his friends and family have now begun leaving tributes on the page, with one person saying they were devastated by his death.
"So sad to hear of the news. Always carried such a happy positive cruisy vibe," said one user.
"My heart bleeds for the loss of our loving and inspiring young friend," said another.
The Burning Man event happens once a year in Nevada's Black Rock Desert, with thousands of people coming together to "create a Black Rock City".
On its website, it's called a "temporary metropolis dedicated to community, art, self-expression and self-reliance".