Willie Mullins has been fined and will be prohibited from attending a racecourse for a period of two weeks, having been found in breach of Covid-19 protocols.
Two of Mullins' staff, Katie Murphy and Steve Jones, attended a meeting at Aintree on November 7 and then were present at Punchestown a week later when they should have been restricting their movements.
The IHRB tweeted: "At a referral hearing of W.P. Mullins (Trainer) following the fixture at Punchestown on 14/11/20, Mr. Mullins was found in breach of rule 272(i), fined E2,500 & prohibited from accessing a racecourse for two weeks for a breach of Covid-19 protocols. Full details in due course."
Further Tweets reported that Mullins' two staff members must both stay away from the racecourse for three months. Jones has been fined 400 euros, and Murphy 200.
A spokesman for the IHRB said: "The two members of staff, Katie Murphy and Steve Jones, represented Willie Mullins on the November 7 at Aintree and also at Punchestown on the 14th so therefore they didn't adhere to the Horse Racing Ireland protocols for racing behind closed doors.
"Those protocols required them to self-isolate for a period of up to two weeks before being allowed to go racing again.
"In addition to that they obtained a barcode to get into Punchestown by answering questions dishonestly.
"They were found in breach of rule 272 (i) which is 'acting in a manner which is prejudicial to the integrity, proper conduct or good reputation of racing' and 272 (ii) which is providing 'misleading information or give false evidence to an official'.
"Therefore Willie Mullins was found in breach of 272 (i)."
Strict protocols on racecourses in both Ireland and Britain have resulted in a number of trainers being prevented from attending meetings for a period of time after being found in breach, among them Aidan O'Brien and Donnacha O'Brien.
The pair had completed the required paperwork before Irish 2,000 Guineas day at the Curragh during the week of resumption in Ireland, but failed to enter the racecourse through the designated screening area.
