It exists in two states: as the colorless gases hydrogen cyanide and cyanogen chloride or in crystal form as sodium cyanide or potassium cyanide.

Michael Young demanded £50,000 from Spalding grower David Bowman warning that he had injected his pumpkins with deadly potassium cyanide.

But animal rights activists said the dogs, including puppies, were administered potassium cyanide with the support of officials.