A Siberian environmentalist has been detained on suspicion of poaching the world’s largest sheep, the argali, media outlets reported Monday.

The Saylyugemsky National Park on the Russian-Kazakh-Mongolian border, which oversees the protection of the argali and snow leopards, said a group of hunters was caught Saturday and charged with administrative offenses.

“They said they arrived to hunt the ibex, but ecologists and local residents know that they haven’t lived on this site” for the past decade, the park said. “The only ungulate recorded here is the argali.”

It identified one of the detained individuals as Ermen S., who it said heads an environmental organization and volunteers at the republic of Altai’s protected natural areas.

The Tayga.info news website, citing an unnamed source familiar with the investigation, said Ermen S.’s last name is Surkashev and that he is a staffer at the republic’s directorate of protected territories. A person with that name also heads the republic of Altai’s Argut environmental foundation that has won a $70,000 presidential grant for preserving the Siberian musk deer, another species threatened by poaching.

Security services apprehended Ermen Surkashev with the two others during a hunting tour near the argali habitat in Altai, Tayga.info reported.

Surkashev was detained along with a Moscow businessman and an Altai-based trophy hunting organizer, the national park and Tayga.info reported.

Surkashev maintained that he was wrongfully accused in comments to the Podyom news website.

“It was a tourist trip,” he was quoted as saying. “What made them think it was argali hunting?”

The Saylyugemsky National Park estimates that only 1,400 argali, which are threatened by overhunting and habitat loss, remained in Russia in 2019.