The several-metre-long white whale was first sighted a few years ago wearing a camera harness near Norway, fuelling suspicions it was being used for espionage.
It has since been nicknamed Hvaldimir, combining the words 'hval' (whale in Norwegian) and the common Russian first name Vladimir.
When first spotted in 2019, the whale's harness was fitted with a base for a small camera with 'Equipment St. Peterburg' printed on the plastic strap.
The biologists who found Hvaldimir were able to remove the harness fixed around his head.
The Norwegian Directorate of Fisheries speculated at the time the whale had escaped from an enclosure where it was possibly trained by the Russian Navy since it was accustomed to human company and would approach ships.
When it was first spotted in a harbour near Norway’s northernmost point, it became a local attraction and was so comfortable with people that it swam to the dock and retrieved plastic rings thrown into the sea.
Moscow has never officially commented on the case.
Where is the Beluga whale now?
On Sunday (28 May), Hvaldimir was seen near Hunnebostrand in western Sweden, further south than its first appearance in 2019, according to Sebastian Strand, a marine biologist with Onewhale, a nonprofit organisation created solely for protecting the health and welfare of Hvaldimir.
Hvaldimir has been moving in the southern direction quicker than its normal pace, Strand said.
Strand noted the whale is moving away from the where Belugas usually like to stay - the colder waters of Greenland and the Russian and Norwegian Arctic.
By Tuesday, Norwegian authorities said the whale had been reported off Lysekill, which sits north of Goteborg, Sweden's second-largest city.
Last week, the white mammal was spotted in the inner Oslo fjord where the directorate urged people to avoid contact with the animal to ensure its safety and wellbeing.
The directorate pointed out that there was a risk of injury for Hvaldimir when more recreational boats than usual gathered in the fjord as people sought to catch a glimpse of a huge US aircraft carrier, the USS Gerald R Ford, which briefly visited the Norwegian capital.
When in Norwegian waters, the beluga whale was considered a protected wild marine mammal, and authorities in Norway have “rejected all inquiries and plans to capture the whale”, according to Olav Lekve of the Norwegian Directorate of Fisheries.
Why is Hvaldimir so far south?
The Barents Sea and the North Atlantic are strategic areas for the Western and Russian navies, which have placed submarines in the zone.
"We don't know why it's moving so fast at the moment," Strand said, acknowledging that Hvaldimir's quest to find a partner could be a possible reason.
“He is a little lonely whale who hopes to find other white whales that he can hang out with."
Carl Bildt, Sweden's former foreign minister, jokingly suggested to Swedish broadcaster TV4 that Hvaldimir should be granted political asylum in Sweden, saying “it is possible that it is a refugee protesting against [Russian President Vladimir] Putin’s war” in Ukraine.
But OneWhale is concerned about his ability to catch food, saying it has already identified signs of weight loss.