A lorry driver has suffered serious injuriesin a crashwith a London minicab and a red Citroen.
The occupants of the other vehicles involved in the "serious" crash at around 5am on Thursday (July 11) have not been injured.
Emergency services remain at the scene dealing with the incident,with the carriageway likely to remain closed between Junction 8 (Reigate) and Junction 10 (Wisley/A3interchange)until mid-afternoondue to a large diesel spillage.
Highways England has advised motorists to find an alternative route,with a diversionavailable here.
Both the motorway and the diversion routes are heavily congested,as is the M23 northbound on approach to theM25at Junction 7.
Officers are now appealing for any witnesses to the crash,or anyone who may have dashcam footage of the driving of any of the vehicles prior to the collision.
Anyone with any information should call Surrey Police on 101,quoting reference number PR/P19155923.