Police believe a third car may have been involved in a collision which left a woman with life-changing injuries.
Officers investigating the crash which took place on the A45 near Wellingborough on Sunday published an appeal for witnesses on Monday.
However, they have today (Wednesday) renewed their appeal for witnesses, including asking for the driver of a third vehicle which may have been involved in the collision to come forward.
A police spokesman said: “A red Ford Fiesta and grey Peugeot 3008 were in collision near to Prologis Park slip road at about 12.10pm on Sunday, January 22, which resulted in the woman driving the Fiesta being taken to University Hospital Coventry via air ambulance.
“Collision investigators are now appealing for the driver of a five door silver Ford Fiesta, who they believe may have been involved in the collision, to come forward.
“It is believed the car, which is thought to be a 2002 to 2008 model, may have been in collision with the red Fiesta, resulting in damage to the front of the car which will include red pain transfer.
“It is understood that the driver did stop at the scene but left prior to police attendance.
“Officers would like to speak to this motorist, or anyone who may have any information about this incident.”
Witnesses or anyone with information can contact police on 101 or Crimestoppers anonymously on 0800 111555.