The Police Ombudsman has sent out over 200 letters to families to inform them investigations into the killings of their family members during the Troubles will no longer continue.
It follows the passing of the Northern Ireland Troubles Legacy Bill which brings all investigations and inquests to an end in May.
The ombudsman has informed some families that there is no longer any prospect of their complaints being investigated before the cut off point.
Victims' group Relatives for Justice which represents some of those that received the letters. said the letters were very impersonal. It said the manner in which they were sent was insulting to the families and added to their pain.
The Police Ombudsman's office said it recognises that families will have been "disheartened and frustrated with receipt of this news, and regrets that some have been disappointed on receipt of this communication".
It added: "In April of this year many families were advised that the office would be unable to investigate their complaints prior to April 2024. A commitment was made to communicate further when the then proposed legacy legislation was progressed.
"Following the enactment of this legislation it was important to advise these families of the impact of this legislation on their complaints.
"The Police Ombudsman is continuing to dedicate her limited historical investigations resources to ensuring that those legacy cases that can be completed and reported on are brought to a conclusion before 1st May 2024."
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