An interim board has been appointed to the national governing body for equestrian sports, Horse Sport Ireland, by Minister for Agriculture Charlie McConalogue.
The former chair, Joe Reynolds, announced he was stepping aside earlier this evening, after what he termed "deep divisions" at board level led to six of the eight directors resigning.
Minister McConalogue thanked previous board members for their service and announced that the former chair of Kerry Group, Michael Dowling, would step in as chair of the board.
He is to be joined by Niamh Brennan, Professor of Management and Corporate Governance at UCD; Zoe Kavanagh, Chief Executive Officer of the National Dairy Council; and Dr Kevin Smyth, former Chief Financial Officer at the Department of Agriculture, Food and the Marine.
The minister said the appointments were "effective immediately" and the interim board will remain in situ until after the Paris Olympics in mid-2024.
He added in a statement: "The sport horse sector is enormously important in Ireland, from a sporting, economic and cultural perspective ... What is important now is that we have a period of stability for the organisation and its staff in the period running up to the next Olympics."
HSI is partly State funded and received more than €7 million from the Department of Agriculture and Sport Ireland last year.
In a lengthy statement, Mr Reynolds said divisions had arisen in "recent months" on the board, that had not been possible to repair.
"Matters came to a head recently when a number of directors voted in a favour of a motion at a board meeting against specific legal advice," he said.
"The course of events led directly to the ongoing board issues becoming irreconcilable."
Mr Reynolds said he offered to stand aside ten days ago, but the minister asked him to remain in place until replacements could be found.
It is understood that board tensions were exacerbated when the HSI went to the High Court, following a board decision, when the department awarded a marketing contract to the Irish Horse Board - duties previously carried out by Horse Sport Ireland.
It is believed that there are also significant difficulties between the HSI and two of the 23 affiliate equestrian bodies.
Two board members - Mary Lambkin Coyle and David O'Meara - resigned on Friday 4 November.
Four others - Lucinda Creighton, Paul Duffy, Tom Freyne and Clare Hughes - resigned on 11 November.
In the last fortnight, two coaches from the Irish eventing team, Grant Wilson and Sally Corscadden, have initiated High Court action against HSI, Joe Reynolds and the Agricultural Trust.