One lane on the M6 northbound was closed following a crash at junction 31 (Samlesbury Interchange), near Brockholes, shortly before 2pm today (July 28).
It has now been confirmed two lorries had collided, reportedly resulting in two men brawling at the side of the road.
Traffic officers quickly rushed to the scene and arrested one of the men on suspicion of assault.
He remains in custody for questioning.
A spokesman for Lancashire Police said: "It looks like we were called shortly before 2pm today (Tuesday) to reports of a collision on the southbound M6 close to junction 31A.
"We attended and found two lorries had collided. Following the collision it was also reported two men had been seen engaged in a physical altercation at the side of the road.
"A man was arrested at the scene on suspicion of assault and remains in custody."
Highways England have confirmed the vehicles have now been removed and the lane closure has been lifted.