An animal rights organisation says Sir Mark Todd's hitting a horse with a tree branch nine times amounts to cruelty, and a four-month ban is a slap on the wrist.
The British Horseracing Authority gave the equestrian a four-month suspension for hitting the horse during a training session which was captured on video.
Two months of the suspension are being served at a later date, so Todd - having served two months of an interim suspension - can return to training immediately.
Spokesman for animal rights organisation Safe, Will Applebe, said the ban wasn't long enough for unacceptable behaviour like this.
"It's a bit of a joke really. It's a slap on the wrist. Now he's essentially back to business as usual," Appelbe said.