Australian police officials confirmed Sunday they were called on board a P&O Pacific Jewel cruise ship Saturday afternoon following reports that a 79-year-old woman had died. The boat was docked off the coast of Cairns, near Australia's Great Barrier Reef. 

Authorities say that Margaret Carlson was believed to have died around breakfast due to natural causes. 

A spokesperson from P&O cruise denied that there was a reported outbreak of the infection on board the ship. “The woman did sadly pass away on board our ship on Saturday,” she said. “But there is no report of a gastro outbreak on board. Our thoughts are with the family during this time.”

According to The Sydney Morning Herald, however, family members dispute the account. It was the 79-year-old's seventh cruise in the decade following her husband’s death and she was excited about the journey after being upgraded to a luxury cabin. She was reportedly travelling with her daughter and grandson.

Carlson soon began showing signs of illness, her daughter said, and was told by medical staff that she had probably brought the sickness onto the ship with her. Her daughter and grandson also allegedly became ill after boarding the ship.

Queensland Health said it had not been informed of gastro on a cruise ship. Gastroenteritis, meantime, is not a "notifiable" condition, thus there is no obligation to report an instance of an outbreak.

One passenger was also medically evacuated from the same ship by helicopter on Monday. The cruise line did not release details about why the passenger was evacauated from the ship. 

Staff on board the Pacific Jewel notified police about the death on Saturday morning. The P&O liner left from Sydney on Sept. 6 for a 10-night "Barrier Reef Discovery" cruise.

Police are still preparing an official report on the woman’s death for the coroner. An autopsy will also be performed.