Officers are looking for witnesses to a fight involving two drivers at the entrance to Lincoln County Hospital.
The clash happened at around 6pm on Sunday, May 13.
Police were told a man driving a brown BMW challenged the driver of a small white car as he “believed it was following him”.
A physical altercation reportedly took place between the two men – one man was kicked and the other punched.
The driver of the small white car, which is said to have had the letters ‘P’ and ‘K’ in its registration, then tried to stop the other driver from getting back into his car.
A Lincolnshire Police spokesperson said: “A vehicle believed to be a dark coloured Toyota RAV 4 may have seen the incident and a bus was also passing.
“We would like to hear from anyone who was in either of these vehicles and witnessed what happened.”
Anyone who witnessed the incident is being asked to call 101 quoting incident number 342 of May 13.