Officials are investigating a suspected outbreak of bird flu after a number of wild swans reportedly died in Windsor.
Seven birds are feared to have died from H5N6 avian influenza, according to the Sun newspaper.
The Department for Environment, Food & Rural Affairs (Defra) confirmed it was investigating a suspected outbreak of the deadly strain in Berkshire, with results expected early next week.
It did not confirm the number of birds potentially affected or the number reported to have died.
Bird flu has been detected in 75 wild birds so far in 2018, including a number of mute swans, Defra's records show.
Recently, two mute swans tested positive in Greater London.
Currently no bird flu has been detected in poultry or kept birds.
All unmarked mute swans on the River Thames, which runs through Windsor, are owned by the Queen as part of a tradition dating back to the 12th century.
This time last year, two swans died after 12 birds were shot with an air weapon and slingshot near to Windsor Castle.