John Edwards, the Information Commissioner, said:
“People have the right to expect that their personal information is kept safe and not disclosed when it shouldn't be. This incident raises serious concerns as it shows how even the smallest of human errors can have major consequences.
“We recognise the potential impact on the people and families affected by this breach, and we expect appropriate action to be taken by the Police Service of Northern Ireland as a matter of urgency.
“The incident demonstrates just how important it is to have robust measures in place to protect personal information, especially in a sensitive environment. The ICO works to support organisations to get this right so people can feel confident that their information is secure, and harms can be prevented.
“Following the report received from the PSNI, we are investigating the matter. Whilst this is a matter of serious concern, we do not yet know the extent to which the personal information was accessed during the time it was exposed. We are working with the PSNI to establish the level of risk and mitigations.”