It comes as a criminal investigation continues into the naming of at least eight ex-police officers in papers unlawfully disclosed to a law firm.

The lawyer for the ex-officers has written to PONI to request a detailed explanation of the leaked information, and to PSNI Chief Constable George Hamilton to query police actions to recover the documents.

The move comes not long after the Police Federation for Northern Ireland (PFNI) called for a full inquiry into PONI’s operation.

In a statement at the time, PFNI chairman Mark Lindsay said: “If PONI cannot be trusted with sensitive information, then there’s a good case to be made to restrict the data. There should be a full investigation by Information Commissioner into what appears to be a blatant breach of the Data Protection Act and the incident should also be reported to the Oversight Commissioner, who has responsibility for all information obtained under investigative techniques.”