The cruise operator added: "We are providing every support to the deceased's friends and family and extend our most sincere condolences to them at this difficult time."
Ambassador Cruise Line said in a separate statement that as of 11:00 BST on Wednesday, 48 passengers were displaying symptoms consistent with gastrointestinal illness, as well as one crew member.
The cruise ship set sail from Belfast on 8 May, before heading to Liverpool the next day.
There are currently 1,187 guests and 514 crew members onboard the ship, according to its operator.
In its statement, Ambassador said there was a reported increase in cases after guests boarded in Liverpool.
It said "a number of guests and crew onboard Ambition have displayed or are displaying symptoms consistent with gastrointestinal illness".
Gastrointestinal illness is a common condition that causes diarrhoea and vomiting. Cases in adults are usually caused by norovirus or food poisoning.
Carol Landa-Vance, who is from County Antrim and is on the ship with her husband, said she noticed on Sunday that "we were not allowed to help ourselves at the self service buffet.
"Condiments were removed and knives and forks were wrapped up and handed to us. The pools were closed and the jacuzzi was also closed."
She said that someone was sick on the bus in front of her, and another was sick on the deck.
"It's a wee bit scary but people are in mostly good spirits."
David Munster, from Dundonald in County Down, is on board with his wife. He said that after departing Liverpool they were informed that a number of passengers had "become ill".
Munster said: "At this stage we don't know if we will be kept on the ship and just have to sit here until this is dealt with, or whether we'll be allowed to get off and see Bordeaux, which is obviously what we'd love to do."
He said passengers were free to use the facilities that were open, but the people who were ill were isolating in their cabins.
Munster had not witnessed people being ill but had seen the "clean-up of people being sick" and said staff had been "very hardworking".
Call555JackChop on May 13rd, 2026 at 15:37 UTC »
It’s because nasty ass people don’t wash their hands anymore, you know how many dudes I watch just walk outta bathroom stalls and right out the door
aka_linskey on May 13rd, 2026 at 12:58 UTC »
Norovirus is the worst. That sounds awful.
fc_dean on May 13rd, 2026 at 12:53 UTC »
Those cruises are a literal bacteria / virus breeding ground, aren't they.