A person has been critically injured after their vehicle crashed down a bank on the Lewis Pass.

A police spokeswoman told chrislynchmedia.com the crash, near Horseshoe Lake, was reported to emergency services at 9.30pm.

It was a single-vehicle accident where the car rolled down a bank, the spokeswoman said.

A St John spokeswoman said they responded with a first response unit, a rapid response unit, a PRIME vehicle, and an ambulance.

Crews assessed and treated one patient, who was then transported to Christchurch Hospital in critical condition.

The road was closed while emergency services rescued the driver.