A 93-year-old man died following a fall from his mobility scooter at the junction of Hall Lane and the A52 in Benington.
The incident happened on October 4 between 11am to 11.15am.
It was later that day that the man attended Boston Pilgrim Hospital but he died on Wednesday this week.
Police are specifically appealing to two members of the public who are thought to have helped the man up.
Call Lincolnshire Police on the collision hotline 01522 558855 with any information.