Devon and Cornwall Police has referred itself to the police watchdog following the death of a man on the A30 near Exeter Airport.
Officers were called to reports of a crash involving a pedestrian and an Audi on the A30 Eastbound carriageway at 5am on Saturday 15 July.
A 26-year-old man was pronounced dead at the scene.
The female driver of the car sustained minor injuries and was treated at hospital.
She has since been discharged.
A 35-year-old woman from Honiton was arrested on suspicion of causing death by careless/inconsiderate driving and has been released under investigation, pending further enquiries.
The road was closed while officers from the Roads Policing Unit and Forensic Collision Investigation Team examined the scene.
It has since reopened and police investigating the incident are appealing for witnesses to come forward.
The force will be making a mandatory referral to the Independent Office for Police Conduct (IOPC) following the incident, due to prior police contact with the deceased victim earlier in the day.
Witnesses, or anyone with information or dashcam footage is asked to contact police by calling 101, quoting log number 177 of 15/7/23.