Three people remain in hospital after a car careered off the road, hit a telegraph pole and landed on its roof in the early hours of Tuesday morning.
The crash happened at 2.40am in Ivinghoe.
The blue Renault Clio which was travelling along the B489 from the direction of Ivinghoe Beacon, approached the junction with the B488 and left the road.
It collided with a telegraph pole before rolling down an embankment into a grass paddock where it landed on its roof.
One of the three men who was in the car was thrown from the vehicle.
The driver sustained extensive bruising and was treated at Stoke Mandeville Hospital.
One of the passengers sustained back and hand injuries and was also taken to Stoke Mandeville Hospital for treatment.
The other passenger sustained extensive facial injuries and was taken to the Luton and Dunstable Hospital.
Anyone with information about the collision is asked to contact PC Steve Leathersich via the Thames Valley Police enquiry centre on 101.
Alternatively, you can contact Crimestoppers anonymously on 0800 555 111.