During the years after the relationship between Norway and China suffered when the Nobel Peace Prize was being award to a critic of China in 2010, Norwegian salmon exporters served the Chinese market through trading companies in Vietnam reveals a documentary by the Norwegian media NRK.
A number of rules and regulations may have been violated by the trading houses.
When the relationship eventually was restored, the redirection was no longer needed.
In 2020, seventeen Chinese businessmen were convicted for salmon smuggling. The court documents show that the Chinese bought the salmon but requested it delivered in Vietnam.
The complicated matter is researched in great detail by the NRK and the article is found here.