A 53-year-old lorry driver was arrested on suspicion of causing serious injury by dangerous driving after colliding with two cars which had stopped in lane one of the M1.
The white Renault articulated lorry was travelling on the southbound carriageway between junctions 18 (Crick) and 17 (M45) at about 6.10pm on Sunday, January 28.
The driver and rear seat passenger of a blue Seat Leon and the driver of a grey Volvo XC90 were seriously injured in the collision and taken to University Hospital Coventry for treatment.
The lorry driver has been released under investigation while enquiries continue.
Officers investigating the incident would like to speak to anyone who may have witnessed the collision or who may have any information regarding it.
Anyone with information can call the Drivewatch Hotline on 0800 174 615.