In another fatal crash in Whakatane, a person was found dead on SH30 near Kope Drain Rd on Saturday night. He was also 17 but police have not yet released his details.
Police suspected speed was a factor in the crash that claimed the lives of New Plymouth man Ronald Victor McMillan and Nepalese national Alekh Acharya.
Mr Acharya, 22, hit 67-year-old Mr McMillan, a pedestrian, in New Plymouth on Saturday afternoon.
In a fourth fatal smash this holiday weekend, Elisha Areli (21) died after crashing a car into a tree in Rotorua on Sunday morning.
Shortly before 3am on Saturday, a body was found on SH1 at Mercer, south of Auckland. Police did not release any further information.
On Sunday, police assistant commissioner Dave Cliff said initial investigations suggested drink-driving, speeding, and in one case a person not wearing a seatbelt were among the factors in the fatal crashes. "Three pedestrians have been killed which is really unusual."
Mr Cliff said some drivers incorrectly thought they only had to exercise caution in known accident black spots.
"The vast majority of these fatal crashes, serious crashes, happen in locations where there hasn't been one before. So there's never a good place to be exceeding speed limits."
Complacency about drink-driving was of concern.
In another case, Mr Cliff said a crash victim was not wearing a seatbelt. "It doesn't matter whether you're travelling 100km/h or 1km/h, you can have a crash anywhere and people must wear safety belts."