Two people are trapped after a car plunged 70m down a bank in the Rakaia Gorge on Friday morning.
The car went off the Rakaia Gorge Rd (SH77), near the Rakaia River in Windwhistle, at about 7.47am due to icy conditions on the road.
Firefighters are on the scene and the Westpac Rescue Helicopter has been sent from Christchurch.
A team of specialist firefighters used for difficult terrain extractions is on standby and will be sent from Christchurch if needed, a fire communications spokesman said.
"We are still assessing the situation. It will be a difficult job to get them out. It is cold, slippery and icy out there," he said.