Jockey Rob James has apologised after a video showed him jumping onto the back of a dead horse.
The Irish Horseracing Regulatory Board has confirmed they have commenced another investigation into the video circulating on social media.
The Board had already launched an investigation into the circumstances surrounding a picture of top trainer Gordon Elliott sitting atop a dead horse at his gallops. An IHRB update on Tuesday afternoon said their Referrals Committee will meet on Friday "to hear evidence and consider an investigation relating to Mr. Gordon Elliott".
James, a leading amateur rider, said he was "heartbroken" by the damage done by his "wholly inappropriate and disrespectful" actions.
"I have become aware of a video circulating of me on social media," he said in a statement to The Irish Field.
"I would just like to apologise for my actions which were wholly inappropriate and disrespectful to a lovely five-year-old mare, who unfortunately suffered a sudden cardiac arrest while at exercise earlier that morning, April 30th, 2016.
"I sincerely apologise to the owners of the mare, the staff who cared for her, the horseracing industry and all followers of horse racing for my actions.
"To try defending my stupidity at the time would add further insult and hurt to the many loyal people that have supported me during my career. I have caused embarrassment to my employers, my family, and most importantly the sport I love.
"I am heartbroken by the damage I have caused and will do my best to try and make amends to those hurt by my conduct."
James recorded a first Cheltenham Festival win last year when Milan Native won the Kim Muir for Gordon Elliott.
Irish horse racing has been rocked by another social media scandal this morning.
The Irish Horseracing Regulatory Board has confirmed they have commenced another investigation into shocking images circulating on various platform.
The IHRB tweeted this morning that they "are aware of further social media content circulating and the matter is under investigation."
It is understood that the latest body blow for the sport relates to a video that shows a man, believed to be a jockey, jumping onto the back of a dead horse.
The Board had already launched an investigation into the circumstances surrounding a picture of top trainer Gordon Elliott sitting atop a dead horse at his gallops.
That meeting is due to take place later this week.
The British Horseracing Authority is also understood to be aware of this latest video. Yesterday they imposed a temporary ban on Elliott racing at British tracks.
Meanwhile, Minister of State for Sport Jack Chambers said that Mr Elliott must be "held fully accountable for his actions"
Chambers told RTÉ's Morning Ireland that: "Consequences are important and he needs to be held fully accountable. "Everything should be on the table. Ireland has to set a high bar when it comes to animal standards."