Police have almost completed their investigation into the fiery crash between a milk tanker and a car in Patea last week.
Three people in the vehicle were killed when it was hit by a Fonterra truck last Thursday.
The tanker driver was found dead at his home on Monday.
His death has been referred to the coroner.
Detective Senior Sergeant Blair Burnett said the police have one or two more enquiries still to make before the case will be handed over to the coroner.
Police were yet to officially name any of the deceased.