The Diamond Princess cruise ship operated by Princess Cruises was being held by Japanese authorities under quarantine at anchor in Yokohama following Japanese news reports that an 80-year old male passenger from Hong Kong boarded the ship in Yokohama on Jan. 20 and disembarked on Jan. 25.
Carnival Corp is one of nine parent companies for Princess Cruises.
The passenger developed a cough the day before embarking but didn't develop a fever until Jan. 30. A day later, he was confirmed to have the virus while in Hong Kong, according to reports.
"Prioritizing the safety and health of our passengers and crew on board, we are currently working closely with the Japanese health authorities to assist in the inspection," Princess said in a statement.
Last week, Carnival got a boost after the company received the all-clear from Italian health authorities that a passenger on one of its cruise ships tested negative for the deadly coronavirus.
Carnival shares declined Thursday after the company said a potential case of the coronavirus onboard a Costa Crociere ship docked at the Italian port of Civitavecchia, near Rome, was being investigated, and that all 7,000 passengers and crew were being quarantined.
Costa Crociere is a unit of Carnival.
However, officials confirmed that the 54-year-old woman, while coming down with an unfortunate bout of the flu, did not, in fact, have the coronavirus. The ship was bound for La Spezia in the Liguria region, with 1,000 crew and 6,000 passengers.
Carnival shares were down 1.03% to $43.07 on Monday.
Editor's note: Story has been updated to reflect Carnival's relationship to Princess Cruises.