Las Vegas, Aug 31 (IANS): The death of a man at the Burning Man festival in the US state of Nevada is being treated as suspicious, authorities have said.

Shane Billingham, 33, was found unresponsive in his car on Thursday evening, the BBC reported on Saturday.

Billingham, a New Zealand national, had "poisonous" levels of carbon monoxide in his blood, the police said.

Bystanders reportedly attempted CPR on Billingham before paramedics arrived.

He was taken to a medical tent, where he was later pronounced dead.

Pershing County Sheriff's Office said on Friday that it was investigating the death as suspicious.

A post-mortem examination found Billingham had "a concentration of carbon monoxide in his blood which would be considered poisonous to human life".

A makeshift memorial for Billingham has been set up at Beats Boutique, the camp where he was staying at the festival.

Burning Man is a music and arts festival held annually in the Black Rock Desert of northwest Nevada, approximately 160 km away from Reno.

Taking place between August 25 and September 2, the festival - attended by tens of thousands of people - describes itself as "a temporary metropolis dedicated to community, art, self-expression, and self-reliance".