The Norwegian Food Safety Authority (NFSA) is testing samples from the farm to test whether the suspicion is confirmed.
The farm, located in Langfjorden in Alta, first warned the authority on June 23 about the suspected outbreak.
The NFSA immediately imposed restrictions on the farm, including increased surveillance and a ban on any transport of fish without special permission from the authority itself.
Mainstream, which is part of the Cermaq group, is the only salmon farmer present in that fjord.
