Three people close to Rory McIlroy made a "concerted effort" to destabilise the golfer's relationship with the sports agency he had signed a deal with, the High Court in Dublin has heard.
They were consultant Donal Casey, who later became CEO of Rory McIlroy Inc; the golfer's personal assistant Sean O'Flaherty, and father Gerry McIlroy, the court was told.
Maurice Collins SC for Horizon Sports Management and two other companies said: "It is a central part of my clients' case that in the period subsequent to January 2013, Mr Casey, Mr O'Flaherty and Gerry McIlroy made a concerted effort to destabilised the relationship between Rory McIlroy and Horizon."
It was the third day of pre-trial applications for orders seeking inspection of mobile phones of Mr McIlroy and others. This is in advance of the hearing of the golfer's claim he is entitled to repudiate a December 2011 agreement with three companies. The defendants deny his claims, and have counter-claimed for damages. A decision on the phones will be given later.
Earlier, Rossa Fanning BL, for McIlroy, said it was "just preposterous" to suggest there was a conspiracy to end the golfer's agreement.