Emergency services do not know for how long a vehicle was down a bank before it was discovered in Dunedin this morning.
A police spokeswoman said they were called to a crash on Blackhead Rd, near Green Island Bush Rd, at 7.50am.
A vehicle had rolled down a bank and was quite far off the road, she said.
"We're not actually sure when the crash actually occurred."
It appeared to have occurred some time prior to 7.50am, when it was reported to police, she said.
A St John media alert said one person was transported to Dunedin Hospital in a serious condition.
Fire and Emergency New Zealand sent crews St Kilda and Lookout Point assisted police and St John.
