Leading Irish racehorse trainer Gordon Elliott says he will help an inquiry into a disputed photograph of him shared on social media.
The image, which some believe has been digitally altered, appears to show the 43-year-old sitting on a dead horse.
Elliott is a highly successful trainer who has won the Grand National three times, including twice with Tiger Roll.
"I'm aware of a photo in circulation on social media," the trainer posted on Twitter.
"The IHRB (Irish Horseracing Regulatory Board) have been in contact with me regarding this photo and I will be co-operating fully with their investigation."
The image appears to show Elliott making a peace gesture while sitting on a dead horse lying on its side. It has the caption "new work rider", although it has been described as a fake by some on social media.
He issued his statement late on Saturday night after the IHRB said earlier that it was "aware of an image circulating on social media and the matter is under investigation".
Elliott, who is based in County Meath, has been approached for comment.
An IHRB spokesman said on Sunday: "The investigation is ongoing and will be dealt with as quickly as possible."
The British Horseracing Authority (BHA) is aware of the image and officials are in contact with their Irish counterparts.
"We hope the Irish authorities will quickly confirm how this shocking picture originated," said a BHA spokesperson.
"Respect for horses is a fundamental value of our sport, contrary to the impression in this picture.
"The IHRB have assured us that the investigation will be carried out as quickly as possible and that they will keep us informed as more information becomes available."
Elliott is preparing a strong squad of runners, including Envoi Allen and Zanahiyr, for next month's Cheltenham Festival, where he has had 32 winners.
Tiger Roll is expected to run in the Cross-Country Chase at Cheltenham before seeking a record-equalling third National triumph at Aintree on 10 April.
Elliott won the Cheltenham Gold Cup in 2016 with Don Cossack, owned by Ryanair boss Michael O'Leary's Gigginstown House Stud.