The crash took place on the anticlockwise carriageway of the M25, between junction 9 and junction 8 in Surrey, at around 12.10pm today (February 7), our sister title London Now reports.
Three men have since been arrested on suspicion of dangerous driving, Surrey Police has confirmed.
One person also had to be taken to hospital as a result of their injuries after the crash.
A spokesperson for Surrey Police said: “There are currently significant delays on the M25 following a multi-vehicle collision between J9 and J8.
“Three men have been arrested on suspicion of dangerous driving.
“One person has been taken to hospital for medical treatment.
“We expect this to cause delays into the evening, so please take this into account when planning your journey and travelling through this area.”
The spokesperson added that police are “particularly interested” in the manner of driving of a black Audi, a blue Cupra, and a silver/grey BMW in the moments leading up to the collision.
Anyone who might have witnessed this collision, or have any dashcam footage that may have captured it, is urged to get in touch with police quoting reference PR/45260014908.
All four lanes of the carriageway from junction 10 to junction 8 were fully shut for more than an hour while emergency services attended the scene on Saturday, with delays of up to 50 minutes building on the approach as a result.
While all four lanes of the M25 have now reopened, drivers have been warned to expect delays “into the evening”.