SalMar has reported a suspected outbreak of infectious salmon anaemia (ISA) at its Bondøya site in Nærøysund municipality in Trøndelag.
The Norwegian Food Safety Authority said the suspicion was reported on 23 May. Restrictions have been placed on fish movements at the site pending further investigation.
It is the second suspected ISA case reported by SalMar in Nærøysund this month.
ISA is a viral disease affecting farmed salmon and is classified as a category C disease in Norway, meaning measures may be introduced to limit spread between sites.
If the diagnosis is confirmed, the Food Safety Authority may order the site to be emptied.