Police used a stun gun in a hospital emergency ward yesterday after they were called to deal with a woman in distress, the Belfast Telegraph can reveal.
It is believed that the young woman in Belfast's Mater Hospital was in possession of a knife and medics feared she was about to harm herself.
Last night the woman was being treated in hospital.
The Police Ombudsman's office has been informed and will launch an investigation.
A PSNI spokesman said: "Police attended the report of a female in distress at a hospital in the Crumlin Road area of north Belfast on the afternoon of Wednesday, October 8."
A spokeswoman for the Belfast Trust said she was not able to give an update on the woman's condition. She added: "There was an incident at the Mater Hospital. Police were called to attend it and it is subject to a police inquiry."
DUP councillor Brian Kingston said he was pleased to hear that no one was injured but that the incident raised concerns.
"It will have been very distressing for everyone who witnessed this incident," he said.
"It is a relief that no one was injured. The PSNI has stated that a Taser was used on a woman to prevent harm occurring and the Police Ombudsman will be informed of this as a matter of routine.
"I understand that the woman has been detained by medical staff under the Mental Health Act and is receiving treatment.
"Those working in the front line of health provision are at times exposed to potentially dangerous situations in which people are in a distressed state or are not in control of their faculties. Any such incident is a cause for strong concern.
"The Belfast Health Trust and hospital management will need to review the circumstances of this incident and the response to it to ensure that appropriate measures are in place and so that any relevant changes can be considered." Earlier this month, the Police Ombudsman reported that police were justified in using a Taser in an incident where a man was threatening to kill himself.
Dr Michael Maguire said officers had acted in a lawful and proportionate manner during the incident in north Belfast last October. He also found that stunning the man, who was intoxicated through drink and drugs and was pressing a knife to his throat, had been necessary.
Stun guns are hand-held weapons that fire two wires that attach to the body and release an electrical shock to incapacitate the target. They have been in use in Northern Ireland since 2008.
In March, the Police Ombudsman found police were justified in using Tasers in five incidents involving people armed with knives. Four had been threatening to harm or kill themselves. The other involved a person who was using a knife to threaten his mother and sister. In each case, the use of a Taser allowed police to disarm those involved.