The stewards scheduled a meeting for Tuesday that will include Santos, Funny Cide owner Jack Knowlton told The Associated Press. One Churchill Downs steward called the photo "very suspicious."
Chief Steward Bernie Hettel, the Kentucky Racing Commission's executive director, said at a news conference he would not comment further on the investigation. Steve Sexton, president of Churchill Downs, also wouldn't comment.
Knowlton said any accusations that Santos might have used an illegal aid to win the race are "just absolutely, totally ridiculous." Funny Cide, a 12-1 shot, became the first New York-bred horse and first gelding since 1929 to win the Kentucky Derby, holding off favorite Empire Maker by 1 3/4 lengths last Saturday.
Commission rules do not prohibit a jockey from holding an object with his whip, other than those specifically prohibited, such as an electrical device that might make the horse run faster. It was not immediately clear what Santos might have been holding besides his whip.
The questions were raised after The Miami Herald published a story about the jockey, along with the photo. A reporter from the Herald brought the photo to the attention of the stewards on Thursday night.
The photo, which ran in several newspapers the morning after the race, depicts a dark area in the space between Santos' right hand and his whip.
"There's absolutely, positively not one iota to this and we're very, very disappointed that an individual can take the luster off what we all consider to be a great victory," said Knowlton, speaking by phone from the horse's barn at Belmont Park in New York.
Knowlton said he would attend the meeting Tuesday even though he plans to take Funny Cide to Baltimore to get ready for next Saturday's Preakness. The stewards — Hettel, Rick Leigh and Jack Middleton — have ultimate authority over a race's results.
Santos told the Herald on Friday he carried an object in his hand during the race and described it as a "'cue' ring to call the outriders."
"Why do you want to write about this negative (stuff)?" Santos said before he hung up the phone at Belmont Park, the Herald reported.
Santos said he was carrying the ring to alert an outrider to his presence. An outrider is a rider aboard a pony that can guide a thoroughbred before and after the race.
However, Santos told the Daily Racing Form on Saturday from Belmont that the Herald misunderstood and that it was a "Q-ray" bracelet that he regularly wears for arthritis. The jockey is from Chile and speaks English with a heavy accent.
Knowlton told the AP that the owners spoke to Santos at the barn Saturday morning.
"He had a bracelet on his arm. He always wears it, and that's what we have here," he said.
However, Santos appears to be wearing a bracelet on his left wrist in the photo, not his right. The Racing Form story did not address what Santos might have had in his right hand besides his whip.
Hettel and Hall of Fame jockey Mike Smith told the Herald they have never heard of a cue ring.
Leigh told the newspaper the photograph looks "very suspicious."
It is unclear whether the dark image in Santos' hand is a shadow, the light green background of the silks worn by the jockey behind him or something illegal. Other photos show Santos firmly grasping the whip with his whole hand after crossing the finish line, the Herald said.
Getty Images photographer Jamie Squire said he magnified his picture to examine it more closely. He added that he was able to "definitely see something in his hand besides the whip."
Brandon Lopez, an editor at Getty, told the Herald the photograph was not altered.
When asked if riders are permitted to carry anything other than a whip, Hettel told the newspaper: "Why would they want to? It's the biggest race of the year. You have enough to do with the whip and the reins that there is no reason to carry anything else."
Santos was voted an Eclipse Award in 1988 as the nation's outstanding jockey and was the leading rider in purse earnings from 1986 to '89. This was his first Kentucky Derby victory.
"It's an unneeded distraction," Knowlton told the AP. "We're trying to get the horse and all the horse's connections ready for the second leg of the Triple Crown."
The Herald notes that in 1999, jockey Billy Patin was suspended from riding for five years after Arkansas racing officials ruled he used a hand-held, battery-operated device to spur long shot Valhol to victory in the Arkansas Derby, an important Kentucky Derby prep. Film footage from that race showed a dark object falling from Patin's hand as he slowed the horse past the finish.
Getting away with the same in one of the nation's grandest sporting spectacles would seem difficult, the Herald says. Not only were there 148,530 witnesses on hand for the Run for the Roses, but a large national TV audience was watching. There were television cameras set up at various points around the track.