Police are at a serious crash south of Whangarei.

A police spokesperson said emergency services were called to the scene at around 3.50pm this afternoon after a vehicle crashed into a ditch on Paparoa-Oakleigh Rd.

The sole female occupant of the vehicle was believed to have been thrown from the vehicle and has been airlifted to Whangarei Hospital in a serious condition.

The Northland Serious Crash Unit is in attendance at the scene. The road is down to one-lane so motorists can expect delays.