Named locally as Hvaldimir, the whale was first spotted off Norway's coast in 2019 wearing a Russian harness.
Having spent years travelling slowly southwards from Norway's far north, the whale has sped up his movements out of Norwegian waters in recent months.
OneWhale said the reason behind his sudden hastiness was unclear.
The tame beluga whale first approached Norwegian boats near the island of Ingoya four years ago. The island is 415km (258 miles) from Murmansk, where Russia's Northern Fleet is based.
