 Halotus , as the Emperor 's official taster , would probably have had a role in the plot , deceiving Claudius into believing the food was safe to consume . He is a prime suspect because he would have had access to everything eaten by the Emperor on the night of his death . It has been suggested that Halotus may have been the murderer but was working under orders of Agrippina . While it is uncertain whether Halotus would have had anything to gain from the death of the Emperor , Agrippina 's political and personal advantage gained by the death of her husband was evident ; with Claudius dead , Nero , Agrippina 's biological son , would be able to claim the throne . It was also known that the animosity between Agrippina and Claudius had grown during the months preceding the homicide . Other notable suspects included Locusta , a professional poisoner , and Xenophon , Claudius ' royal physician , who , in line with the suggestion that the poison was not immediately fatal , is said to have carried an ailing Claudius out of the banquet , taken him to his room and forced a poisoned feather into his mouth on the pretence of encouraging him to regurgitate . Others say Xenophon used poisoned gruel . 
