(CNN)Bear Grylls has landed himself in hot water and faces a potential fine after killing and cooking a frog while filming in a protected national park in Bulgaria.
The British adventure TV presenter filmed an episode of his Running Wild series in Bulgaria's Rila mountains in 2017 alongside US ballroom dancer Derek Hough, and was seen gutting and cooking a frog.
But Bulgaria's environment ministry said Thursday that Grylls had violated the nature reserve's environmental regulations by killing the animal, swimming in a lake and lighting a fire.
"It is evident from the film material that during the shooting there were breaches to the regulations and rules of conduct in protected areas: entering and swimming in the water basin of the Karakashevo lake, lighting a fire, and catching and killing an animal," a spokesperson for the ministry said in a statement to the AFP news agency.
Officials from the department said they were considering fining Grylls and Hough between €250 and €2,500 ($284-$2,834), while the production companies, Bear Grylls Ventures and Electus, could face a fine of between €500 and €5,000 ($567-$5,670).
The department reported that Grylls and his film crew had been briefed over the rules governing the park. It added that it would also investigate the park authority, in order to determine whether officials who accompanied Grylls had failed to enforce the regulations.
Both Bulgaria's environment ministry and Grylls' representatives did not immediately respond to CNN's request for comment.
Grylls has faced sharp criticism in the past from conservationists and animal rights campaigners for his treatment of animals on screen.
Claire Bass, director of Humane Society International/UK, said Friday that no animal should be killed as a result of celebrities playing "survival games."
"Yet again Bear Grylls' animal killing activities are quite rightly coming under fire," she told CNN. "It's time for TV to dump this tired routine of men charging around the wilderness dominating wildlife and killing for ratings. It shows a callous disregard for the natural world and treats animals like mere props."
She added that higher ethical standards in broadcasting are required in order change perspectives on "acceptable ways to behave" in regards to animals.
David Attenborough, the renowned broadcaster and naturalist, has previously criticized Grylls for his treatment of animals. "Bear Grylls will have to answer for himself," he told The Sun in 2018, adding that his own nature shows, which include Blue Planet 2, would never "willingly kill" any animals in order to get a shot.
Rila National Park, in the southwest of the country, is Bulgaria's biggest national park. It was established in 1992 and is home to rare and endangered animal and plant species.
Grylls' shows have previously shown participants killings animals including pigs, turkeys and caiman crocodiles.
His most high-profile participant was the then-US President, Barack Obama, who accompanied him on an expedition in Alaska in 2015, during which they ate a salmon pre-gnawed by a bear.