A teenage girl who was killed by a car while on foot on the M5 had fled a police vehicle before she was struck, it has emerged.
Avon and Somerset police said the motorway was closed between Bridgwater and Taunton in Somerset after the fatal collision involving a pedestrian and a car at 11pm on Monday.
The force said a mandatory referral was made to the Independent Office for Police Conduct (IOPC) watchdog because of the recent prior police contact.
On Tuesday, the IOPC revealed the 17-year-old girl was being transported to custody in a police vehicle and left the vehicle shortly before the collision.
An IOPC spokesperson said: “We have started an investigation into the circumstances surrounding the death of a 17-year-old girl who was struck by a vehicle on the M5 near Taunton last night.
“We were advised by Avon and Somerset police that the girl was being transported to custody in a police vehicle and had got out of the vehicle shortly before the collision.
“We sent our investigators to the police post incident procedure to begin gathering evidence. Our sympathies are with the girl’s loved ones and everyone affected by her death.”
Avon and Somerset police have been approached for comment.
Earlier, the force said the victim’s family had been informed and were being supported by a specially trained officer.
“No one else was injured in the collision,” the statement said. “The M5 is expected to remain closed for some time while inquiries are carried out.”