NZTA said SH79 near Geraldine was closed at the intersection of Pleasant Valley and Tiplady Rds.
A state highway in Canterbury is closed after a truck crash early this morning.
The New Zealand Transport Agency said State Highway 79 near Geraldine was closed at the intersection of Pleasant Valley and Tiplady Rds.
Two people were seriously injured, police said.
Police reiterated the road was closed and said motorists should avoid the area if possible.
Inquiries into the circumstances of the crash were ongoing, a spokeswoman said.
SH79 is a popular route for sightseers travelling to the Mackenzie Country, being a key highway between Christchurch, Lake Tekapo and Twizel.
Fire and Emergency New Zealand was called to the crash about 5.15am, a spokesman said.
Two fire crews were sent from Geraldine and Temuka.
His mate deliberately struck the deer with a ute, an act that was posted to social media.