The crash was first reported shortly after 1.30pm today (August 19), between junction 23 (South Mimms) and junction 24 (Potters Bar).
A car has reportedly come off the westbound carriageway, leading to delays of up to 30 minutes.
Pictures from the scene appeared to show police vehicles next to an embankment bordering the motorway.
National Highways said that Bedfordshire, Cambridgeshire and Hertfordshire Road Policing Unit were at the scene.
2 lanes (of 4) are closed on the #M25 anti-clockwise between J24 (#PottersBar) and J23 (#SouthMimms) due to a vehicle that has left the carriageway. @roadpoliceBCH are on scene.
There are 30 minute delays and approx. 4 miles of congestion on approach. pic.twitter.com/l3nyka8UxA
— National Highways: East (@HighwaysEAST) August 19, 2023
Two lanes have been shut off causing a traffic jam of four miles and normal traffic conditions are not expected until after 5pm this evening.
Police have been contacted for more information about the incident.
