Police are investigating after an incident at Spalding bus station at about 6pm on Tuesday in which an off-duty officer arrested a 59-year-old Wyberton man for a public order offence.
The man was later de-arrested and taken to hospital for treatment for a pre-existing medical condition.
Witness statements and CCTV evidence is now being gathered any witnesses who have not already provided their details to police are asked to contact Pc Paul Smith.