There was a two car collision on State Highway One, just north of Hunterville on Friday 2 April at 11.45am. Three people died at the scene and a fourth person has since died of injuries sustained from the crash.
Constable Paul Johnson of Hunterville Police is investigating the cause of the accident.
The preliminary enquiries and reconstruction of the accident scene it would appear the two vehicles have collided head on.
Constable Johnson is keen to speak with anyone who saw a bluey silver Alfa Romeo travelling north, or a silver Mitsubishi Sigma travelling south around the time of the accident.
"In particular, it is important that I locate a female student who apparently stopped at the accident scene and spoke to another witness, this person was travelling from Massey University and heading to Taupo, she appears to be the only eye witness to the accident" said Constable Johnson.
Witnesses to the accident can contact their local police station or Constable Johnson at Hunterville Police on 06 321 9111.