A Victorian man who was missing for 24 hours in the News South Wales outback has been found dead.

The two men and one woman, all believed to be from Victoria, went missing on Tuesday after their car broke down about an hour from Broken Hill, in the state's far west.

The woman walked 25 kilometres through scorching desert to the town of Acacia Downs yesterday morning where she called police.

They used GPS to trace the call to the Mutawintja National Park, about 150 kilometres north east of Broken Hill.

Police reached her at around 8pm last night and she told them she had left two men at the water hole.

They later found the body of a 33-year-old man she was travelling with.

A coroner's inquest will be held to determine the cause of death.

Police will not say how he died, but no one has been arrested in relation to the death.

A 21-year-old man was found nearby suffering from exposure and dehydration.