It is feared a disease dreaded in the salmon farming industry has struck in Scotland.

An outbreak of infectious salmon anaemia (ISA) is suspected on two salmon farms in Loch Nevis and Loch Snizort in the West Highlands.

If the disease is confirmed thousands of salmon on the affected farms will have to be slaughtered and production stopped for a considerable period while disinfection is carried out.

All movement of fish from the suspect farms has been banned, and as a precaution a similar ban has been placed on a further seven salmon sites further south in Loch Nevis and Loch Creran.

It is the first time ISA has been found in this country, and the only other countries to encounter the disease are Norway and Canada.

Farms owned by four companies are involved, and one, Marine Harvest McConnell, said yesterday that 270,000 fish bought from Norwegian-owned Hydro Seafoods were suspected of having the virus.

The virus does not affect humans although humans handling infected fish could pass it to other fish if good hygiene methods are not followed. Inspectors from the Marine Laboratory in Aberdeen are investigating the affected sites and if the disease is confirmed a clearance and disinfection programme will begin.