The price of salmon is set to soar as global supplies have been hit by an infestation of sea lice.

The parasites, which are less than 1.5cm long, have already caused wholesale prices to rise by as much as 50 per cent in the last year.

The outbreak comes after stocks had been depleted by a deadly algae bloom in Chile, the world's biggest producer of farmed salmon.

Now farms in Scotland and Norway have seen their fish affected by large numbers of the lice, known as Lepeophtheirus salmonis.