Ards and North Down Borough Council has launched a probe to establish if elected representatives have been leaking confidential documents to loyalist blogger Jamie Bryson.
Councillors are understood to have been told about the investigation into the major information breach last week.
They have also reportedly been warned that phones could be audited as part of the probe.
The Belfast Telegraph reports that the investigation relates to the leaking of confidential legal advice, obtained by the council, into the implications and obligations around the post-Brexit arrangements.
Earlier this year, Mr Bryson posted on X, that councillors had voted down a proposal to accept a £55,000 grant to implement aspects of the Northern Ireland Protocol.
He was challenged about his post by Alliance MP Stephen Farry, who said ratepayers in the borough would be left to “cover the cost of statutory functions”.
But Mr Bryson later said he had “secret legal advice” about the issue and also posted a picture of a document from Ards and North Down Borough Council that stated ‘Report Classification — Legal in Confidence’.
Complaints are understood to have been made by council representatives that the confidential legal advice was provided for the purpose of assisting Mr Bryson.
The council will now look to establish the source of the leak amid other claims also that Mr Bryson was allegedly involved in drafting motions for some elected representatives.
There are claims that he had “secret meetings with a group of at least five unionist councillors, formulating motions and drafting letters for them” and that he was also being “leaked the council’s confidential legal advice”.
Council members were last week told that they should inform the office of chief executive Stephen Reid if they were responsible for providing Mr Bryson with the report detailing the confidential legal advice.
