According to Norwegian media organisation NRK, marine experts have said they believe this was a specially-trained whale, working as part of the Russian navy to carry out secret underwater military operations.
A team from Norway's Directorate of Fisheries - trained to release sea animals from netting and other foreign objects - responded to the scene and helped a local fisherman free the whale. "I don't see why they would equip those whales with harnesses", he told ABC News.
Russian Federation has a naval base in the region. The mammal's behaviour also sparked suspicion as it repeatedly approached the vessels and was very tame. Belugas are native to Arctic waters.
The white beluga whale was sighted last week in waters near the Norwegian village of Inga.
Professor Audun Rikardsen told the BBC that the harness "was attached really tightly round its head, in front of its pectoral fins and it had clips". He said there was a GoPro attachment, but no camera.
Experts believe a beluga whale spotted off the coast of Norway was trained by the Russian navy.
Then in 2017, Russia's TV Zvezda, which is owned by the defense ministry in Moscow, aired a report on a Russian navy program to train beluga whales, seals and dolphins for similar purposes.
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This has prompted speculation the animal may have escaped from a Russian military facility.
Little is known about Russia's use of marine life for its military, although The Washington Post reported that the Defense Ministry in Russian Federation advertised that it was looking to buy five Bottlenose dolphins for unknown purposes in 2016.
The dolphin facility in Crimea used to be under Ukrainian control, but was seized by the Russian navy in 2014, when Russian forces took over the peninsula.
He said there have been no reports of programs or experiments involving beluga whales. That country and others, including the United States, have renewed their focus on the Arctic in recent years as climate change has melted ice and opened new shipping lanes.
The Russian military is reportedly renewing its Cold War-era training of marine mammals, considering such animals useful tools in defending naval bases, assisting military divers and even attacking intruders, The Guardian explained.
The navy website also says the animals are used to detect unauthorised personnel underwater who could potentially harm U.S. ships.