Two men who died in a Boxing Day crash along the southern Canterbury coast have been named by police.

Christchurch man Horton James Hill, 80, and 31-year-old Matthew James Gilchrist from Oamaru were killed in the crash at Glenavy on the Waimate Highway on Tuesday morning.

Police said an investigation into the cause was continuing on Friday, but Mid-South Canterbury area commander Inspector Dave Gaskin of Timaru on Wednesday said it was "pretty apparent" the northbound vehicle was travelling at well over the 100km/h speed limit when the crash happened.

READ MORE: Fatal Glenavy crash - 'Men would still be alive if one wasn't speeding'

"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.

"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 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 thrown from his car.

The southbound car was taken to Timaru so firefighters could free the driver's body.

 

The road toll for the holiday period - which started on Friday and will end on January 3 - currently stands at seven.

During the 2016-17 Christmas period there were 19 deaths on roads.