Police said it was unclear what caused the two-van, T-bone collision at the intersection of Coast Rd and State Highway 1 about 1.10pm.
Sergeant Graeme Evans confirmed at the scene alcohol was not considered a factor but would not comment further while the crash was investigated.
A St John spokesman said the male driver of one vehicle was flown to Dunedin Hospital and the female driver of the other van was taken by ambulance.
Euro Campers managing director Volkmar Wollenweber confirmed it was one of his company's campervans involved in the crash and it was rented by a German woman in her 30s.
He had not been contacted by police as to who was at fault and could not comment further on the crash.
Both vehicles were overturned on their sides following the crash.
The male driver was "dazed'' and "had blood on his face'', a woman, who arrived at the scene shortly after the crash, said.
People at the scene directed traffic before emergency services arrived.
"It seemed interminable before anyone arrived,'' she said.
St John sent two ambulances, a rescue helicopter and a rapid response unit to the scene, the St John spokesman said.
One side of the road remained blocked for more than an hour after the crash and traffic was delayed.
Senior Sergeant James Ure, of Dunedin, said the cause of the crash remained under investigation and no charges were laid as of yesterday.
