An expert on rare books has confirmed to the High Court that he has "irretrievably erased and irreversibly destroyed" all electronic copies of letters written by the late Jackie Kennedy to an Irish priest.

Eoin Felix O’Neill from Cahir in Co Tipperary also consented to permanent injunctions preventing him from representing himself as the owner of the letters or publishing or reproducing them in any way.

The case, taken by Sheppard's auctioneers, returned to the High Court this morning after temporary injunctions were granted earlier this month.

Mr Justice Peter Kelly was told many of the matters raised before the court "fell out of contention" because a decision had been made that an auction of the letters would not now proceed.

Mr O'Neill's lawyers also confirmed to the court that all copies had been permanently destroyed.

The archive of the correspondence with Fr Joseph Leonard, a Vincentian priest who lived at All Hallows College in Dublin, was due to be sold at auction next month.

Mr O’Neill was present at the college when the letters were disclosed to Sheppard's.

He had been a client of the firm for some years and had agreed to act as a consultant to it concerning rare books for which he was paid expenses and commission of 3% of the "hammer price", the court was previously told.

Sheppard's had sought the injunctions amid concerns that he had photographed some of the letters and may have been behind the publication of the letters in the Boston Globe.

They alleged he had made "strange comments" at a meeting and had said he was going to "get the letters sold."

In a sworn statement submitted to the court, Mr O'Neill denied he had taken any unauthorised actions and said the application for the injunctions had been unnecessary.