The men, two aged 24 and one aged 25, died when the white Toyota Hilux they were travelling in rolled on a gravel road about 25km from Lake King, in Western Australia, media reports said.
The Otago Daily Times understands the three were childhood friends who moved to Perth together several years ago.
They were believed to be flatting together in Perth before Saturday's crash, the ODT was told yesterday.
The Perth Now website reported the single-vehicle crash was discovered early on Saturday morning.
Emergency services were called to the scene about 7.30am but arrived to find the men were already dead, the website reported.
It was unclear what caused the crash and whether speed, alcohol, fatigue, inattention or lack of familiarity with the conditions played a role, it said.
Their names were yet to be released, but Dunedin police confirmed yesterday one of the men was from Winton, a second was from Manapouri and the third from another part of Southland.
Police in those areas had been asked to inform next of kin in Southland of their deaths yesterday, Senior Sergeant Craig Dinnissen said.
A Western Australia police spokesman said he expected the names to be released today.
Family of the men were travelling from New Zealand to Perth to visit the crash location.
An investigation into the circumstances surrounding the crash was continuing.
Further details on the inquiry were expected to be released today, he said.
