A 70-year-old man from Mablethorpe died and another passenger was seriously injured after a car crashed into a tree in a village near Alford.
The collision involving a Renault Modus happened on Main Road in Withern just before midday on December 22.
Two passengers, a man and a woman, were both seriously injured and taken to hospital. The female driver was not seriously injured.
Lincolnshire Police announced on Thursday, December 31 that the man has since sadly died and they are now investigating the collision.
Any witnesses or anyone with information or dashcam footage is being urged to contact Lincolnshire Police on 101 or via email at [email protected] quoting incident reference number 149 of December 22.