Finnish Customs has completed a preliminary investigation of suspected illegal import of around 36,000 kilogrammes of whale meat from Norway to Finland in 2022.
The whale meat was imported in the form of sausages for dogs, half of which contained minke whale and the remainder poultry, according to the agency.
Minke whales are protected by the multilateral treaty CITES, a convention protecting animal and plant species threatened by international trade.
The export of minke whale products from Norway, as well as their export to the EU, is prohibited.
According to Finnish Customs, the imported dog sausages were not sold on the open market, but had been ordered by a private operator.
The sausages were used to feed a large number of sled dogs, the agency said, adding that the main reason whale meat is used in the feed is its favourable price.
Customs said that five individuals are suspected of serious nature conservation and customs clearance offences.
The agency said it has forwarded the case to the Prosecution District of Northern Finland for consideration of charges.