A 40-year-old woman suffered serious head injuries after falling off her bike in Timaru last night.
A police spokeswoman said emergency services were called to the incident in June St just after midnight.
The woman was biking home and was not wearing a helmet when she fell and hit her head, the spokeswoman said.
She was taken to hospital by ambulance in a serious condition.
Alcohol and other distractions may have been a factor, the spokeswoman said.
The police Serious Crash Unit were investigating.