Police arrested a 26-year-old man who claimed to be in possession of a gun when he was refused entry to a mental health centre at Lincoln County Hospital.
The hospital was put on lockdown after around 7.30pm on Monday, July 25 when a man was reported to have been making threats of violence.
The man, who was not a patient at the hospital, was refused access to the Peter Hodgkinson Centre and claimed to have a gun.
Lincolnshire Police attended the scene and doors to the main reception area of the hospital were locked, affecting both patients, visitors and staff.
Pat Coates, Inspector for Lincolnshire Police, said: “We became aware of a disturbance outside Lincoln County Hospital at 7.30pm last night.
“A 26-year-old man had been refused access to the Peter Hodgkinson Centre and was claiming to be in possession of a firearm.
“We believed this to be false but we take any claims of this nature seriously and attended the scene. The man was not armed but we did arrest him for breach of the peace.
“The man was detained overnight and released from police custody this morning once he was in a calm state. Staff at the hospital decided to temporarily close the site as a matter of precaution.”
The hospital reopened again at around 9.30pm.
A spokesperson from United Lincolnshire Hospitals Trust, which runs Lincoln County Hospital, said: “We were made aware of an incident involving a member of the public just after 8pm last night.
“As a precautionary measure we took the decision to lock the main entrance doors to Lincoln County Hospital and doors in proximity to the incident.
“For a short while people were unable to leave the main reception until the incident was resolved by Lincolnshire Police. We can confirm that nobody was harmed.”