The beloved celebrity animal was found dead due to apparently unnatural causes at the estimated age of 14-15 years old, which is half a typical beluga whale’s average lifespan. His death was announced by the nonprofit organization Marine Mind, which was devoted to monitoring him.

“It is with heavy hearts that we share the news of Hvaldimir’s passing,” the group said in an Instagram post. “This morning, after receiving a sighting report from a local, our team arrived to find Hvaldimir floating peacefully in the water. It is not immedately clear what caused his death, a necropsy will be conducted to determine his early passing.”

The Norwegian Directorate of Fisheries confirmed his death in a statement to People and said it would be performing the autopsy.

“Due to the great attention around the whale, the Directorate of Fisheries decided to have an autopsy done in an effort to determine the cause of death,” it said. “The autopsy is conducted by the Norwegian Veterinary Institute, and the conclusion will be public in two or three weeks.”

One Whale founder, Regina Haug, stressed in a video message posted on Instagram that Hvaldimir’s death was certainly not natural and that there were visible wounds. She accused an unnamed person of spreading misinformation about his death to cover up its unnatural nature.

Hvaldimir, whose name is a combination of the Norwegian name for whale and Russian President Vladimir Putin, captured popular attention after being discovered by fishermen off the coast of Norway in 2019. He was abnormally friendly and receptive to humans and was found to be wearing a camera harness that read, “Equipment St. Petersburg.” Theories quickly circled that he was being used for Russian espionage, though Russian authorities never acknowledged the prospect.

Russia and the United States train sea mammals such as dolphins for national security roles — Russia openly admits to training dolphins to guard harbors in Crimea. Some are trained for combat roles, such as killing hostile divers or attaching mines to the hulls of enemy ships.

However, other people poked holes in the theory, with Russian Col. Viktor Baranets pointing out to broadcaster Govorit Moskva that it made little sense to label equipment used in sabotage.

“If we were using this animal for spying, do you really think we’d attach a mobile phone number with the message ‘please call this number’?” he asked rhetorically.