A teenager who died on the M5 after being hit by a car was "being taken into police custody".

The 17-year-old was being transported to custody by Avon and Somerset Police before the incident, the Independent Office for Police Conduct (IOPC).

An IOPC spokesperson said an investigation had been launched, adding: "Our sympathies are with the girl’s loved ones and everyone affected by her death."

The girl was being transported to custody in a police vehicle, and exited the car shortly before the crash.

Teenager who died after being hit by car on M5 was 'being taken into police custody'Google Street View/National Highways

The 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.”

Drivers have been warned of hours-long traffic due to the crash