A Canadian woman who had been travelling with the victim, a 33-year-old man, escaped from the van after the attacker drove off in it, police said.
The attack on the two tourists occurred at around 3.20 a.m. in Raglan, a coastal town in the Waikato region of New Zealand's North Island. Police found the vehicle, with the dead body inside, at 8 a.m., a few kilometers away.
Police did not release the name of the victim.
New Zealand is a popular tourist destination, especially among Australians. Last year, a 22-year old British woman was killed while on a backpacking tour of the country.