The incident happened between Junction 29 (Hornchurch) and Junction 28 (Brentwood, A12) at 12pm yesterday (December 12).
The clockwise carriageway reopened at 3pm with one lane closed, but the anticlockwise side remains fully shut.
All lanes were fully reopened just after 11.30pm last night.
During the incident, motorists were faced with severe delays, with up to three hours of congestion and 12 miles of traffic reported on approach to the anticlockwise closure at Junction 29.
National Highways Traffic Officers and area crews were assisting at the scene and managing traffic.
Vehicles trapped within the closure were being turned and released from the back of the queue.
We are awaiting official information on the nature of the crash from the Metropolitan Police, who are leading the investigation.
