French authorities have confined more than 1,700 passengers and crew members to a cruise ship docked in Bordeaux after a suspected norovirus outbreak, officials have said.

The vessel, Ambition, which is carrying 1,233 passengers, most of them British or Irish nationals, arrived in Bordeaux on Tuesday. About 50 people had shown symptoms of the virus, French health officials said.

A 92-year-old passenger died on the cruise on Sunday. However, the operator, Ambassador Cruise Line, said the guest did not report any symptoms of gastrointestinal illness and the cause of death had yet to be established, pending a coroner’s full report.

Ambassador confirmed there were 48 active gastrointestinal illness cases among the passengers and one among the crew on the vessel, which was on a 14-night cruise. It also said French shore authorities had instructed guests and crew members to remain onboard.

The ship departed Belfast on Friday and Liverpool on Saturday. Figures from the operator showed an increase in cases after the embarkation of guests in Liverpool.

A statement from the company said: “We would like to reassure guests that we take any illnesses aboard our fleet extremely seriously. Enhanced sanitation and prevention protocols were immediately implemented across the ship in line with established public health procedures following the initial reports of illness.

“The comprehensive health and safety measures introduced include increased cleaning and disinfection measures in public areas, assisted service in selected dining venues and ongoing guidance to guests regarding hand hygiene, including regular hand washing, use of hand sanitisers and the prompt reporting of any symptoms to the onboard medical team.”

The statement said medical consultations regarding gastrointestinal illness were being provided free of charge.

The authorities in Bordeaux had requested they conduct a routine review of the ship’s health status and records, Ambassador said, adding that a specialist medical team and “sanitation consultants” had also been dispatched to the vessel.

While onboard, the specialist medical team collected existing samples for laboratory testing at Bordeaux University hospital, with results requiring a minimum of six hours to be processed.

“While the investigation and testing are ongoing, all guests and crew have been instructed to remain onboard under the direction of the local shore authorities,” the operator said. “Once clearance is granted, guests will be permitted to disembark.”