Mr Troy is today trying to contact the various embassies connected with those involved in the crash. He expected to be able to release the victims' names tomorrow.
He said the car was travelling north when it has crossed into the path of the truck, however he wouldn't confirm reports that the car hit the truck side-on or backwards.
The critically injured driver - a 21-year-old man - was airlifted to Waikato Hospital by Taupo's Greenlea Rescue Helicopter.
Conditions were treacherous at the moment and it was snowing when emergency services arrived at the scene, he said.
"It was cold and there were patches of ice on the road and when emergency services arrived it was snowing as well."
He confirmed the occupants of the car were not skiers.
The 16 tonne, four axle truck was carrying waste substances but none of it leaked from the truck.
Mr Troy urged motorists to take care while travelling along the Desert Rd this winter.
"The Desert Rd is notorious for changing conditions. You can have beautiful weather on one side of the hill and on the other side you can have black ice and ice and snow so we encourage all motorists to take extreme caution when travelling through the Desert Rd area and in fact on all roads in New Zealand and just drive to the conditions."
The crash scene was horrific, according to an NZME reporter who flew over the scene yesterday morning.
She said there was a lot of smashed glass and the area was surrounded by ice and scattered with snow.
The crash is likely to cause huge disruption as holidaymakers head to Mt Ruapehu.
MetService this morning issued a warning for the Desert Rd saying snow showers were expected above 900 metres until around midday Monday and around 1cm of snow could accumulate.
Turoa and Whakapapa ski fields were closed for several days last week due to a lack of snow but have since reopened.
Whakapapa received 21cm of snow in the last 24 hours, while Turoa received about 15cm.
A MetService spokesman says conditions were "freezing"in the Rangipo area overnight and was about 2 degrees at 8am today with the road itself receiving a dusting of snow overnight.
Meanwhile, the latest Ministry of Transport road deaths data proves a dire read, with 181 people - excluding those killed in this morning's crash - have died on the country's roads compared to 176 at the same time last year.
The statistics show 127 of those killed were men and 54 were women. June and February had proved the deadliest with 31 people dying in each month.
