Thames Valley Police is appealing for witnesses to a road traffic collision in Milton Keynes.
A white Mercedes-Benz C-Class hit a tree on Denbigh Road at the junction with Lyon Road shortly after 1am on Saturday (30/9).
The driver, a 23-year-old man from Luton, suffered a bleed on the brain. He was taken to Milton Keynes University Hospital for further treatment, but has since been discharged.
A passenger, a woman in her twenties, suffered a fractured back. She was taken to the same hospital for further treatment, where she remains.
The driver was arrested on suspicion of causing serious injury by dangerous driving, dangerous driving, drive whilst unfit through drink, failing to stop when required by a constable and driving without third party insurance. He has been released on police bail.
Investigating officer PC Amy Harnett, of the Joint Operations Roads Policing Unit, based at Milton Keynes police station, said: “I am appealing for any witnesses to this collision, whereby a man and a woman have sustained serious injuries, to please come forward.
“Anyone with dash-cam, video doorbell or CCTV footage that might assist our investigation should also please get in touch.
“You can contact us by calling 101 or by making a report on our website, quoting reference number 43230439485.”