Businessman Denis O’Brien’s case against Dublin-based Red Flag Consulting “will have every public relations firm in the city wondering if they are committing the tort of conspiracy”, a High Court judge has remarked.

Mr Justice Colm MacEochaidh made the comment before reserving judgment on Mr O’Brien’s application for orders compelling Red Flag name its client who commissioned a dossier of material about him which he alleges is evidence of a campaignn to damage him. The judge hopes to rule by the end of the law term on December 21st.

Mr O’Brien claims Red Flag and its unknown client are involved in the alleged campaign and he wants the client’s identity now so as to sue that client, along with Red Flag, for damages for alleged conspiracy and defamation

Among Mr O’Brien’s concerns is whether the dossier, particularly material in it about the planned IPO of Digicel earlier this year, which did not go ahead,was sent to hedge funds, Michael Cush SC, for Mr O’Brien, said.

It was clearly relevant whether the client is a “benign hedge fund” or a rival of Mr O’Brien’s, counsel added. The issue was not whether the dossier was published to millions but “who it was sent to”.

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Mr O’Brien rejected claims by Red Flag of a “lack of candour” by him related to how he learned of Red Flag’s involvement in the dossier, counsel added.

Opposing the application, Michael Collins SC, for Red Flag, argued it has a duty of confidentiality to the client and there is no legal basis for the order, which was a “fishing exercise” involving a “procedural morass”.

There was no “clear and unambiguous” evidence of the alleged hostile campaign against Mr O’Brien.

Mr O’Brien had previously been refused orders to seize computers and devices from Red Flag’s offices. Instead, he got freezing orders preserving material on the devices and further orders permitting imaging of the material. He had deferred another application for orders to inspect the imaged documents.

Now he wanted this “exceptional” order which would cause “irreparable harm” to the firm’s consulting and communications business already damaged by the proceedings, counsel argued. Many of the firm’s clients were concerned data of theirs held by Red Flag had been forensically imaged.

Ireland could be seen as a jurisdiction where public relations firms may potentially be compelled to disclose their clients identities, counsel said.

Mr O’Brien, counsel earlier submitted, had failed to be “frank” in a sworn statement last October, the basis for his application for orders to seize devices of Red Flag, concerning how a USB computer memory stick with the dossier of material about him “materialised” on his Dublin office desk.

There was “implausibility stamped over all this”, counsel said. Mr O’Brien initially gave no information about where the memory stick was delivered to but later said it came to his offices in an unmarked envelope with the decryption code written inside the envelope. There was no explanation how someone “waltzed” through security in the “centre of his empire” to leave an envelope on his desk.

In closing arguments, Mr Cush said it was correct Mr O’Brien learned from an examination of metadata in the dossier, rather than through an investigation, of Red Flag’s involvement with the dossier. Mr Collins’ use of adjectives such as “odd” and “implausible seemed to be suggesting Mr O’Brien was “lying” in his first affidavit but that was not the case, counsel said.