The Police Service of Northern Ireland (PSNI) on Wednesday confirmed that it declared a "critical incident" due to a data breach.
"Following a routine Freedom of Information (FoI) request data contained within a spreadsheet was published on a legitimate FoI website. This included the surname, initials, rank/grade, role and location of all serving officers and staff. This data was available to view on the website for a period of up to three hours before it was removed," the PSNI said in a statement.
Law enforcement and its partners are investigating the incident and have taken measures, including providing security advice, to support officers and staff that could be at risk, the PSNI added.