A man was taken to hospital with serious injuries after his car left the road.
The single-vehicle collision happened shortly before 4am on Sunday October 16 on West Farndon Road near Woodford Halse, about 200 metres north of Warden Grange.
Northamptonshire Police say a black Audi A3, driven by a 26-year-old man, for reasons yet unknown, left the road and came to rest in a ditch.
The driver was taken to John Radcliffe Hospital with serious injuries.
Witnesses, or anyone with information about the collision, are asked to contact the Northamptonshire Police Collision Investigation Unit on 101 or call the Drivewatch Hotline on 0800 174615.