Update, August 23, 2017: Prosecutors have dropped the investigation into alleged abuse, concluding there is not sufficient evidence of criminal or administrative violations.

The Hannover Adventure Zoo in Germany is coming under attack after the release of hidden camera video footage that shows handlers striking elephants.

The video, from the animal welfare organization PETA Germany, reveals zookeepers yanking young elephants’ heads to the ground, thrusting sharp training tools called bull hooks into their necks, and using whips to make them perform circus-like tricks. The elephants seem to be cowering and trying to run away from the keepers.

According to PETA Germany, the three elephants involved, all three years old, are named Sitara, Taru, and Yumi.

Carol Buckley, an independent expert in captive elephant welfare and founder of Elephant Aid International, an organization that promotes humane captive elephant care, later reviewed the material. “I watched hours and hours of video,” she wrote in an email. “It was appalling, sickening. The elephants are petrified. The trainers’ actions are vile and heartless.”

Buckley said in a statement that the elephants at the Hannover zoo “live in fear on a daily basis.” The keepers “use force unsparingly,” she wrote. “They inflict pain for even the slightest perceived infraction.”

Established in 1865, the Hannover zoo is one of Germany’s most popular, drawing more than a million visitors each year, and its dozen elephants are a major enticement.

PETA Germany began its investigation last May, filming the elephants from the visitors’ perspective, says senior campaign manager Peter Hoffken. Then in September the organization gathered footage using hidden cameras in areas out of public view.

Buckley wrote that among other incidents, the video shows the trainers “repeatedly using both hands—something I have never seen before—to embed the hook into the sensitive tissue of the top of the neck and head. It appears to be the standard response when an elephant hesitates, is not moving fast enough, or is not executing a trick precisely enough for the trainer.”

View Images Visitors watch elephants in their enclosure at the Hannover Zoo. Photograph by Ole Spata, picture-alliance, AP

Scott Blais—a former elephant trainer at a safari park near Toronto, Canada, and founder of the Global Sanctuary for Elephants, in Brazil—also reviewed the video. “The speed at which these elephants respond to commands and the reaction to even the slightest threat of the hook being used is extraordinary,” he wrote in an email. Blais described what appeared to be a gang beating “when one elephant is attempting or threatening to get away and showing hints of aggression. Within seconds two other trainers enter with hooks ready to strike. The young one already knows what this means and quickly follows command.”

Hoffken says Hannover is the only zoo in the country that still features elephants performing circus tricks for the public, which is why PETA undertook the investigation. “We knew that elephants don’t perform circus tricks voluntarily.” In some of the footage, he says, the elephants can be seen turning in a circle while standing on a platform or sitting on their buttocks with their front legs up in the air.

National Geographic asked the zoo to comment. It sent a written statement along with a link to a webpage responding to the allegations.

The statement says that independent experts, including professors from Hannover University of Veterinary Medicine, have been enlisted to examine the elephants and that the state attorney is investigating the matter.

Hannover denies that its elephants do routine shows for the public. “The elephant shows have not been given for several years now,” said Andreas Casdorff, the zoo’s director. Instead during feeding times the staff give talks that “convey knowledge about the animals and their biology.”

The statement notes that there have been calls for the keepers to be suspended from their duties but “that elephants kept in ‘free contact’ need just these keepers, with whom they are familiar.” It continues, “Regular training sessions are important because they occupy the animals and make it possible to carry out medical examinations and routine care.”

TRAINING ELEPHANTS

Zoos generally use one of two methods to manage elephants: protected contact or free contact. With protected contact, keepers and elephants are separated at all times by a barrier such as a fence. Free contact means that the animals and keepers are in the same space and that keepers use direct physical contact to control them. According to Carol Buckley, the Hannover zoo’s use of free-contact dominance—a method preferred by circus trainers—causes “utter submission by the elephant.”

“Protected contact can provide all the advantages of free contact without the need to dominate the elephant,” explains Olaf Töffels, vice chair of the Germany-based European Elephant Group, which monitors captive elephants in Europe. He says that protected contact can help prevent accidents with keepers, facilitate medical care, and give elephants room to make their own decisions.

In Germany 56 percent of elephants in captive institutions are subject to the free-contact system, Töffels says. That’s in contrast to Europe as a whole, where free contact is used on a third of elephants. “Germany is quite outdated,” he adds.

The European Association of Zoos and Aquaria (EAZA)—which facilitates cooperation among its more than 350 members in Europe and Middle East, including the Hannover zoo—allows either method. The appropriate use of the bull hook is clearly defined by EAZA, according to David Williams-Mitchell, the organization’s communications manager. Its “use should not result in physical pain for the animal or psychological distress,” he wrote in an email.

EAZA’s elephant welfare standards, which Williams-Mitchell said are being updated, are based on the five domains of animal welfare: nutrition, environment, physical health, behavior and mental state.

This is the first incident of elephant abuse against Hannover zoo that has come to EAZA’s attention, according to Williams-Mitchell. He says EAZA is taking the claims seriously and is scrutinizing the video footage with the zoo to confirm its accuracy and to ascertain whether the zoo is complying with EAZA’s free contact standards. (Read EAZA’s statement here.)

He cautioned that the video should be examined carefully. “We have so far seen the footage PETA has released, but this may not represent the full story. Our responsibility for the welfare of elephants and indeed all animals in our care requires us to look at all the evidence impartially.”

EAZA’s findings about the zoo’s conduct could be announced at the end of April. According to Williams-Mitchell, if there’s clear evidence of systemic abuse of the elephants, illegal activity, or long-standing incompatibility with EAZA values, Hannover zoo’s membership could be terminated.

Töffels, of the European Elephant Group, says that his organization has had complaints about the zoo’s treatment of its elephants since as long ago as 2004.

PETA Germany is pressing charges against Hannover zoo’s elephant keepers and against the zoo’s management.

Christina Russo is a freelance writer who has reported on animal issues for more than a decade. Follow her on Twitter.