British Horseracing Authority chief executive Julie Harrington condemned the "reckless and dangerous" actions of a protester who ran on to the Epsom track after the Betfred Derby had started, with 31 arrests made on flat racing's blue riband day.
The protester broke on to the home straight in the early stages of the race, but was quickly pursued by police and security staff. Moments later a woman tried to jump the fence in front of the grandstand as police officers rushed to stop her.
Angry onlookers could be heard screaming, with one man shouting, "kick her head in", while police threw her to the floor and handcuffed her just as the horses thundered past the finishing line.
Animal Rising had threatened to "cancel or severely delay" the Derby, but the premier Classic went ahead as planned, with Auguste Rodin securing victory for Aidan O'Brien and Ryan Moore.
Harrington thanked the police and security teams for their speedy response, but criticised the behaviour of the protester involved.
A statement said: "We strongly condemn the actions of the individual who ran onto the track after the Betfred Derby had started.
"Despite Animal Rising having previously stated on multiple occasions that they would do nothing to jeopardise the safety of horses and riders, this reckless and dangerous behaviour did exactly that and I am grateful to Epsom's security team for their swift response to ensure the race could be completed safely.
"I would like to extend my thanks to the staff at the Jockey Club and my colleagues at the BHA, who have worked tirelessly to ensure the Derby could be staged safely, and to the race’s participants who cooperated fully during what were shortened preliminaries. I also want to thank Surrey Police for their decisive actions ahead of the Derby."
Police arrested 31 protesters attempting to disrupt the Derby, including 12 in the grounds.
A spokesman for Surrey Police said: "We can confirm that 31 people have been arrested in connection with planned criminal activity at the Epsom Derby Festival this afternoon.
"Eleven people were arrested at addresses in Mitcham and Byfleet in the early hours, following warrants based on intelligence received ahead of the Epsom Derby Festival. A further eight people were arrested after their vehicle was stopped on Canons Lane in Burgh Heath at around 10.20am this morning.
"All were arrested on suspicion of conspiracy to commit public nuisance and remain in police custody.
"A total of 12 people have been arrested within the Epsom Downs racecourse since the event began this morning, also in connection with planned criminal activity.
"One man was arrested after he ran onto the racetrack after a race had started. He was quickly removed by event security and police officers, meaning the race was not disrupted."
