Trainer Emmet Mullins has been fined €5,000 and banned from attending any racecourse for three months after breaching health screening protocols at Leopardstown last week.
Mullins had been refused entry as he didn't have the required barcode but was later spotted at the parade ring on CCTV footage.
Due to coronavirus, entry to all racecourses is strictly limited at present, with only approved, essential workers being admitted.
Mullins told the Racing Post that he accepted he had made a serious mistake, which was motivated by a desire not to leave a groom alone with an important runner.
The nephew of champion jumps trainer Willie also asked for the fine to be donated to frontline healthworkers.
"I accept the findings of today's hearing. I apologise for my actions, it was done without thought and in the heat of the moment. I won’t be appealing, however, I have made a request to the IHRB that I donate the funds to our frontline workers."
Communications manager for the IHRB Niall Cronin said: "A lot of work has gone into getting racing back and it is absolutely imperative that we all work together to keep racing safe by completing the health-screening process.
"This is necessary to continue racing. Complacency in this regard simply cannot be tolerated."