Police are appealing for information after a 78-year-old man was found in the road with a serious head injury near Grimsby.
The man was found just before 4pm on August 28 by a passing motorist outside Riby Grove Farm at Riby.
He was taken to hospital but died the following day as a result of his injuries.
It appears the man fell from his bike, which was also at the scene, but officers have not ruled out the possibility that another vehicle could have been involved.
A spokesperson for Lincolnshire Police said: “We would like to speak to anyone with information relevant to the incident.
“In particular, it is believed that a silver Range Rover may have passed the scene, and officers are keen to trace the occupants who could be important witnesses.
“Please call 101 with incident number 394 of the August 28 if you have any information that could assist this enquiry.”