Gardaí in Cork are understood to be ready to make further arrests in relation to a serious incident which occurred on the main Cork to Mallow road last Saturday.
A video of the May 5 race was posted on youtube showing vehicles swerving onto the hard shoulder as two men race ponies on the main road. The original uploader has since removed the clip.
A man in his 20s was arrested following the incident. He has since been released without charge.
The Irish Society for the Prevention of Cruelty to Animals has condemned the incident, and said "sulky" racing is becoming a major problem in many towns and cities across the country.
ISPCA director Barbara Bent said the ponies are galloped on the roads when they are "only babies, and they never really recover".
She said the ISPCA had found ponies throughout the country who were "only skin and bone, with fright and trauma in their eyes".
A spokesperson for Traveller resource centre Pavee Point called on Traveller groups, gardaí and local authorities to find a resolution together to "respect both Traveller culture and the law of the land".