On Friday (January 12), a white Volkswagen Golf was involved in a crash with a white Toyota Aygo on the A4074 Oxford Road, Dorchester between Shillingford and Berinsfield at around 7.30am.
It has also been reported that a black car, possibly a Tesla, may have also been involved but this vehicle has not been traced.
The driver of the Toyota Aygo, a man in 30s was taken to the John Radcliffe Hospital with serious injuries.
He remains in the hospital but his injuries are not thought to be life-threatening.
The driver of the Golf, a man in his thirties was taken to hospital with minor injuries but was later discharged.
No arrests have been made.
Investigating officer PC Shaun Kipling of the Joint Operations Roads Policing Unit, said: “We are investigating this collision that happened on Friday morning.
“We are appealing for anyone who may have witnessed this collision or anyone with dash-cam footage of the incident to please come forward.
“Additionally if anyone with CCTV along the A4047 in the village of Shillingford could please provide their footage from 7am and 7.30am that would be appreciated.
“Footage can be provided through our online portal page or if you have witness info please call 101 reference 43240016933.”