Officers are trying to locate a man who may be injured after being involved in a single vehicle collision in Stroud on Saturday (28 March).
Police were called to an unclassified road between Edge and Whiteshill shortly before 8pm following reports that a member of the public was flagged down by the man who asked them to call the police.
The man, who is believed to be the passenger of the blue Citroën C4 hatchback, left the scene before police arrived.
He was described as being a white man who was wearing a red top, it is unknown if he sustained any injuries and officers would like to check that he is ok as the car is believed to have rolled.
The collision took place near The Rudge Hill nature reserve and officers were unable to locate the man despite conducting searches in the local area along with colleagues from NPAS and the Fire Service.
The driver of the car, a man in his 50s and from Stroud, was taken to Southmead Hospital in Bristol with serious injuries where he remains at this time.
Investigating officer, PC Tim Griffiths said: “We are very keen to speak to anyone who may be able to help us with the movements of the Citroën in the hours leading up to the collision, or anyone who may have witnessed what happened.
Alternatively you can also anonymously contact Crimestoppers on 0800 555 111.