According to the report, Russia's veterinary agency Rosselkhoznadzor has been working in in league with Russian importers and producers to block Norwegian fish by claiming to find large quantities of bacteria in Norwegian deliveries.
In recent weeks, Norwegian exporters have seen consignments of cod, pollock, herring and mackerel refused due to their high bacterial content, a problem they have experienced since at least 2006.
"The measures from Rosselkhoznadzor were related to agreements between its management on one side and the Importer Association and the participants in the cartel on the other side," the report said.
The Russian Competition Authority's report noted that the agency had been unable to produce laboratory samples proving that the Norwegian fish had not met Russian quality standards.
Arne Aarhus, the head of the Norwegian salmon exporter Ocean Quality, told Norway's DN newspaper that two Russian importers pressured him to sign exclusive contracts with their companies.
"It was said to us that if we signed contracts, we would never get problems with the Russian veterinary authority. On the other hand, if we didn't sign these agreements, the results of laboratory analyses would prove to be "bad", and export of products from our factories to Russia would be subject to a ban," he said.