Officials from the United States Centre for Disease Control are investigating a further outbreak of the norovirus on board the Sea Princess cruise ship.
Based in San Francisco, the vessel has more than 350 cases of norovirus in the past two months.
However, the owners of the vessel – Princess Cruises – blamed passengers for brining the virus on board.
The Sea Princess reported 53 of its 2,196 passengers on the Princess Cruises ten-day Alaskan trip that left the Port of San Francisco on June 19th were affected by the virus.
This is the fourth time since May 10th this ship has had an outbreak of the virus.
The first reported instance was aboard a ten-day cruise that left May 10th, where 44 people were taken ill.
On the May 20th cruise, 128 out of 2,053 passengers reported symptoms.
Finally on the May 30th voyage, 142 out of 2,128 passengers were affected.