Environmentalists criticised locals in the Chilean town of Punta Delgada for desecrating the remains of a blue whale which beached on 18 February.
Pictures show members of the public posing for selfies on top of the the dead mammal and the message "I love you Ana" scratched onto one of its fins.
Both Greenpeace and the Chilean Agriculture Ministry moved to condemn the behaviour – the ministry employed a quote from Mahatma Gandhi.
"The greatness of a nation and its moral progress can be judged by the way its animals are treated," it said.
Local reports say the huge animal attracted large crowds when it washed up on the shore in the south of the country.
Gabriela Garrido, a researcher at the Museum of Natural History, told media he had seen people climbing on the body for photographs and children kicking the carcass.
Photographs of the whale have gone viral on Twitter, showing people sitting on top of it and graffiti etched into its blubber.
"I was shocked to see the situation so out of control... I felt a lot of anger, a lot of powerlessness," Garrido told La Nacion.
The researcher said he believed the 20m-long specimen is around two years old and died from starvation.
Garrido was one of the first scientists to arrive at the beach following news that a blue whale had beached.
"It is very painful to understand how a person can do such a thing," she said. "This would not happen with a dog, which is more charismatic."
Greenpeace's oceans coordinator, Estefania Gonzalez, echoed the sentiment: "The fact that people marked the whale with loving messages and enjoyed taking selfies is a sad demonstration that there are still people who regard animals as playthings.
"The images we have seen are very sad. Not only for the blue whale that has ended up stranded, but especially because of the attitude of people to this majestic and endangered species."