In a tweet, Princess Cruises said a crew member who previously served on the Grand Princess was transferred to the Royal Princess ship over two weeks ago, prompting the Centers for Disease Control and Prevention to issue a "no-sail order" for the ship until the individual was tested for COVID-19.
The test results have not been released.
The Grand Princess is the ship off the coast of San Francisco with at least 21 confirmed cases of novel coronavirus, including 19 crew members and two passengers. A total of 46 people were tested for COVID-19.
Cruise line officials said the crew member is "past the maximum incubation" of the virus and "never developed any respiratory symptoms or fever," adding that the person never had contact or exposure to those infected.
There are more than 3,500 people on the ship, which departed San Francisco for a Hawaiian cruise February 21. The cruise was scheduled to end in San Francisco Saturday.
Grand Princess cruise carrying at least 21 infected with COVID-19 to disembark passengers at Oakland port, officials say
Those who purchased fares for the Royal Princess would receive a full refund as well as credit for a free sail in the future.