Lawyers for Independent News and Media have told the High Court there is no "culture of deference" in the group towards its major shareholder Denis O'Brien.
INM also rejected suggestions by the Office of the Director of Corporate Enforcement that the former chairman of INM, Leslie Buckley, had "untrammelled" influence in the company.
The ODCE made the allegations as part of its application to the court to have inspectors appointed to INM due to its concerns about how the company is conducting its affairs.
Senior Counsel Paul Gallagher, for INM said the suggestions that had been made were of immense concern to INM and to its directors, who were very experienced people of "unimpeachable integrity".
He said their stewardship of the group was recently endorsed at a general meeting of shareholders.
Yesterday, lawyers for the ODCE outlined the concerns that had led to the application to have inspectors appointed.
These included the removal of INM's data from October 2014 and its interrogation by third parties outside the jurisdiction.
The ODCE is also concerned about the circumstances surrounding the proposed acquisition of radio station Newstalk for a "grossly inflated" sum and the proposed payment of a €1 million "success fee" to Island Capital, a company owned by Denis O'Brien, in relation to the sale of shares in an Australian media group.
Mr Gallagher said that when the alleged data breach was brought to INM's attention, it was in the context of a serious dispute between former INM CEO Robert Pitt and Mr Buckley.
He said there was a very thorough investigation by independent reviewers, whose integrity was not in question.
INM had taken legal advice throughout all this, he said, and had approached the matter in a very thorough manner, based on advice.
He said the powers given to the ODCE were so broad and their consequences so serious, that there were ramifications as to whether or not the court should appoint inspectors.
The ODCE said inspectors are necessary to investigate a range of matters concerning the alleged data breach.
Senior Counsel Brian Murray said the office wanted to know who benefitted from it and why was an invoice issued to Island Capital and paid by another Denis O'Brien company, Blaydon Limited.