Mid-South Canterbury area commander Inspector Gaskin, of Timaru, told the Otago Daily Times it was "pretty apparent" the northbound vehicle was travelling at well over the 100km/h speed limit when the crash happened less than 1km north of Glenavy on State Highway 1.
"If you want to be hard-nosed and callous about it: if he was travelling at the speed limit, he would still be alive, and so would the other gentleman," Gaskin said.
"Pretty clearly, from visiting the accident scene, it was obviously an incredibly high-impact crash. Two vehicles coming together at 100km/h in opposite directions produces an awful lot of kinetic energy - but one of the vehicles was travelling well in excess of that speed.
"One of the vehicles as a result of the impact has split and basically broken in half - half of that vehicle has ended up probably 40m to 50m up the road and across the fence and in a paddock," Gaskin said.
The driver of the northbound vehicle that split in half was ejected from his vehicle.
The southbound vehicle was taken to Timaru so firefighters could extricate the driver's body.
Their deaths brought the road toll for the holiday period to seven.
The holiday period this year started at 4pm Friday and ends 6am on January 4.
Other road victims are:
• Rotorua woman Jie Hu died in a crash on SH5 at Hamurana on Christmas Eve. Three others were injured.
• Waipukurau man Harry Nepe-Apatu died in a crash on Pourere Rd in Central Hawke's Bay on Christmas Eve.
• Boney Biju died on his way home from his 21st birthday party after his car left the road and hit a tree near Hanmer Springs on Christmas Eve.
• Fijian national Lalita Devi was a passenger in a car that crashed on SH14 at Maungatapere on Saturday.
• On Saturday, taxi driver Abdul Raheem Fahad Syed, 29, died in central Auckland after his car was hit by another.
- additional reporting Otago Daily Times
