Circus officials have said in the past that the PETA photos do not show punishment or abuse, but represent humane and professional animal training.
PETA's war against Ringling Bros. escalated recently when the animal rights group asked the feds to shut the popular circus, accusing it of elephant torture and brazen coverups.
"They've lied, they've tampered with evidence and they've thwarted the inspectors," said Jeff Kerr, general counsel for the People for the Ethical Treatment of Animals.
In a letter delivered April 12, PETA asked the Department of Agriculture to revoke or block the April 28 renewal of the animal exhibitor license issued to Feld Entertainment, which owns Ringling Bros.
"Abusive and violent treatment of animals ... is part and parcel of Ringling's traveling circus, which requires powerful animals, many of whom were once wild, to learn and perform tricks that are alien to their nature," writes PETA president Ingrid Newkirk.
Circus officials could not be reached for comment, but they have always insisted their animals are well cared for.
Past attempts to prosecute the circus for the same or similar claims have been unsuccessful.
A lawsuit brought against Ringling Bros. by a former trainer alleging rampant elephant abuse was dismissed in December by a judge who ruled the trainer had no standing to sue the circus.
PETA has filed a series of abuse complaints in the past to little effect, but the group hopes to get a more favorable hearing from the Obama administration than its predecessor.
"This is the first time we've taken all the evidence and put it together to show that this is not just one bad trainer, having one bad day, with one bad elephant," said Debbie Leahy, PETA's director of captive animal rescue. "This is chronic and systemic."
PETA says it has amassed 700 pages of documents, videos and photos alleging a history of abuse at the circus ranging from "breaking" baby elephants with electric prods and sharp metal hooks to whipping a tiger until it collapsed and lost control of its bowels.
"The only way you can get a several-ton elephant to stand on his head is from fear of pain," Kerr said. Last year, the Daily News was first to report on the group's undercover video showing elephants being beaten backstage at the Greatest Show on Earth.
PETA also alleges a pattern of coverups, including lying to inspectors after animal injuries and hastily installing just the visible parts of a cage cooling system after a lion named Clyde died of heat stroke in a train crossing the sweltering Mojave desert in 2004.
Frank Hagan, a veteran Ringling Bros. lion handler who had asked the circus to stop the train and was later fired, told PETA he was threatened by circus lawyers to keep quiet about the big cat's death, PETA told The News.
Several weeks ago, a circus elephant named Dumbo stomped its handler to death in Pennsylvania - a coincidence of timing that PETA says underscores their argument that animals shouldn't be forced to perform tricks.