The M25 is currently closed between J22 to J13 in both directions due to a police led incident near South Mimms. Highways England has resources deployed working to assist the police.
Diversion route details and guidance is as follows;
Anti-clockwise: Hollow Black Square route. From M25 Junction 23, take 4th exit onto A1(M) north towards Hatfield. At A1(M) J3, take 1st exit and head south on the A414 towards St Albans. At London Colney roundabout take 1st exit onto the A1081 towards London to re-join the M25 at J22.
Clockwise: Hollow Black Triangle route, The clockwise diversion is the reverse of the above anti-clockwise route.