An autistic girl who was hit by a car and killed on the M5 after jumping out of a moving police car had been able to remove her handcuffs before making her doomed escape, a report has found.

Tamzin Hall, 17, who had been arrested for assault and criminal damage, was being taken into custody by two officers in a police car on November 11 last year when the tragedy occurred.

An inquest hearing at Wells Town Hall later that month was told, Tamzin, who was a student, got out of the car and crossed the road before climbing the crash barrier.

The police vehicle stopped on the northbound carriageway of the M5 between junctions 25 at Taunton and 24 at Bridgwater shortly after 11pm.

She was hit by a vehicle driven by a member of the public travelling on the southbound carriageway and was pronounce dead at 11.10pm after sustaining fatal head, neck and chest injuries.