P&O has sent passengers who travelled on board the Oriana a letter advising them to take "extra precautions" to prevent the spread of the norovirus.
The letter says that the company suspected that the illness was "inadvertently introduced on board by embarking passengers" because of "currently elevated Norovirus activity throughout the United Kingdom".
It advised passengers that "the case numbers decreased rapidly during the cruise" and that "the ship has undergone an additional and extensive disinfection".
As cases of the norovirus soar across the UK, fresh guidance is issued by clinicians on how to treat the symptoms.
The number of confirmed cases of the winter vomiting bug, norovirus, is 72% higher than at this time last year, health experts have said.