Horse Racing Ireland has announced all registrations of horses under the ownership of Supreme Horse Racing Club have been voided following an alleged persistent failure to provide requested information.
HRI said it had "consistently sought, and not received, the requested complete members' information for horses running under Supreme Horse Racing Club".
Entries for Supreme horses were suspended last month.
The syndicate - which is responsible for Magners Cheltenham Gold Cup favourite Kemboy - will no longer be allowed to own or part-own horses registered under Rules in Ireland.
A statement from HRI read: "Despite repeated requests, Supreme Horse Racing Club has failed to provide the members' details required under Horse Racing Ireland Directive 15 Racehorse Ownership, and as a result of not receiving this requested information, HRI is unable to stand over the shareholding of each horse - a fundamental aspect of any owner registration.
"After consulting with our legal advisers, the decision has been taken to void the owner registration for all horses run under Supreme Horse Racing Club in accordance with powers under HRI Directive 15 and Rule 123 (iv) of the Rules of Racing.
"Horse Racing Ireland is disappointed that it is necessary to take this step but due to the lack of engagement and failure to provide the necessary information there is no alternative but to withdraw approval of the club and to cancel its registrations as a recognised club."
"A meeting was arranged with the club's trustee, Steve Massey, for 4 November which he failed to attend without explanation"
It added: "Following complaints from Supreme Horse Racing Club members, and the introduction of Directive 15 - Racehorse Ownership in July, HRI met with Supreme Horse Racing Club trustee Steve Massey on 31 July, 2019. At that meeting there was a commitment by Supreme Horse Racing Club to file the necessary paperwork with HRI.
"There was repeated correspondence in August, September and October, seeking members' information from Supreme Horse Racing Club, which yielded no or inadequate responses.
"With further concerns having been raised with HRI over the administration of the club, on 7 October HRI notified Supreme Horse Racing Club that no withdrawals could be made from the club's HRI account until full members' details were provided.
"This request was reaffirmed on 17 October and with limited information forthcoming from Supreme Horse Racing Club, the club's owner registration was suspended on 22 October."
It went on: "A meeting was arranged with the club's trustee, Steve Massey, for 4 November which he failed to attend without explanation. No subsequent correspondence has been received, including in response to a final deadline this week, and Horse Racing Ireland has therefore made the decision to void the club's registrations."
Jason Morris, director of racing for HRI, said: "Horse Racing Ireland has received a significant amount of correspondence from concerned members of the club since we suspended the registration last month, and we will be in contact with any of the club members we have details for, to update them on our decision today.
"We will be sharing our information with our colleagues in the BHA. We have also reported our concerns around the administration of the club to the relevant authorities."
Morris added: "This week we have met with solicitor Patrick Kennedy of PJ O'Meara Solicitors in Thurles, who has been approached by a number of Supreme Horse Racing Club members laying claim to ownership of the horses.
"That grouping has expressed their intention, over time, to form a new ownership structure. We will continue to work with this group, and others, should they materialise.
"HRI is open to accept the re-registration of these horses under accepted ownership structures. HRI cannot adjudicate as to the shareholding of these horses.
"In order to do so, HRI advises members to seek their own legal counsel or contact Patrick Kennedy in order for agreement to be found among the shareholders of each horse."