"Northern Territory Police are calling for witnesses to a crash in which one person has died and two others have been injured during the Finke Desert Race earlier today [Monday]", police said in a statement.
It added that the fatal crash took place 35 kilometres (21 miles) from the start/finish line.
"A male spectator aged in his 50s was seriously injured as a result of the crash and medevaced to the Alice Springs Hospital, and the navigator of the vehicle, a woman aged in her 50s, received minor injuries", the statement read.
Another man in his 60s died at the scene, the police added.
The area has been cordoned off and an investigation is underway.