Police are urging people who come across road crashes not to interfere with the scene following a double fatal accident in Waikato yesterday.
Serious Crash Unit investigators were still working to establish the cause of the crash between an east-bound Honda Accord and a westbound Volkswagen-hatchback at Piarere, acting Waikato road policing manager Senior Sergeant Jeff Penno said.
"Initial indications on the cause are that the Honda was on the wrong side of the road as the vehicles approached a corner on SH29 and the vehicles collided by the Piarere Hall, about 1400m from the intersection with SH1," he said.
"Two people travelling as passengers in the Volkswagen died of their injuries in the crash, they were 21-year-old Rose-Ana Leigh Mitchell-Kingi and 22-year-old Eruera Eriata Munro, both of Tauranga."
Mr Penno said the front seat passenger in the Honda suffered critical chest and abdomen injuries while three other people, including both drivers suffered moderate injures.
"All four were flown to Waikato Hospital by helicopter, we understand the deceased had been returning from an indoor netball game in Hamilton."
He said those first at the scene did their best to stabilise the injured before emergency services arrived.
One bystander thought he was doing the right thing by clearing debris from the road with a bucket equipped tractor, Mr Penno said, but he warned against altering crash sites.
"In the case of serious injury or fatal crashes they need to be investigated and you really don't want traffic driving through the scene as it puts first responders at risk.
"In addition to that clearing debris from the road removes items from where they fell making it harder from an investigators perspective. We are acutely aware of the need to get the balance right between accurate investigation of road trauma and freeing up closed highways."
Mr Penno said police needed to honour the dead by carrying out an accurate investigation as possible to attribute culpability where it fairly lays.
"To do this we need crash scenes to be left as near to how they looked at the time of the crash as possible."