An expert in rare books has handed a file into court containing copies of all the letters written by Jackie Kennedy to an Irish priest.
Eoin Felix O'Neill also gave an undertaking not to represent himself as the owner of the letters or release any extracts from them.
The letters, written by the late Mrs Kennedy to Fr Joseph Leonard between 1950 and 1964, will be sold at an auction by Sheppards auctioneers on 10 June.
Mr O'Neill was present at All Hallows' College in Drumcondra in Dublin when the 14-year correspondence was discovered.
The court heard today that Mr O'Neill made copies of all the letters, which were handed to Mr Justice Peter Kelly this afternoon.
Mr O'Neill's barrister said all electronic copies have been deleted.
Last Thursday, the High Court granted temporary injunctions against Mr O'Neill, from Cahir in Co Tipperary, after extracts from the letters were published in the Boston Globe newspaper.
MJ Fine Art Ltd, trading as Sheppard's Irish Auction House, also succeeded in getting an order preventing Mr O'Neill from disclosing any trade secrets of the firm.
Sara Moorhead SC said Mr O'Neill strongly disputes many of the assertions made against him last week.
She said he will submit an affidavit on Wednesday.
Mr Justice Peter Kelly said the letters he received today will be kept in a safe in the central office of the court until a full hearing is heard on 29 May.