A woman has died and a number of people have been injured in a crash following a police pursuit.
Essex Police said the collision on Parklands, Waltham Abbey, involved three vehicles and happened just before 10pm on Thursday.
The woman died at the scene.
A statement from the force said: “The incident has been referred to the Independent Office for Police Conduct as it followed a police pursuit involving one of the cars, which officers from the Bedfordshire, Cambridgeshire and Hertfordshire road policing unit had attempted to stop on the M25.”
The force has not disclosed the age of the victim, or the exact number of people injured.
The road has been closed and is expected to remain shut for some time.
Witnesses and people with dash-cam footage are asked to call the Serious Collision Investigation Unit on 101.