The tycoon and the unknown mastermind

Denis O’Brien alleges that an unknown ‘mastermind’ is behind a dirty tricks campaign to undermine his business interests

Denis O’Brien is suing PR firm Red Flag over the contents of a USB stick brought to his desk by persons unknown EPA

Shadowy figures and unanswered questions dominate Denis O’Brien’s High Court conspiracy action against PR consultants Red Flag.

Mr Justice Colm Mac Eochaidh will rule this side of Christmas whether to lift the veil on the firm’s client who commissioned an allegedly defamatory dossier about the businessman.

O’Brien believes the file was designed for an American audience and intended to damage his reputation and his international business interests, including his aborted Digicel IPO last ...