At least 91 passengers have been hit with what is believed to be Norovirus on the first day of a 10-day cruise.
Sun Princess' next cruise is a seven-night itinerary out of Brisbane departing August 20, with calls at Airlie Beach, Cairns, Port Douglas and Willis Island.
When a cruise ship is infected, it can quickly spread due to the contained nature of travel.
"Out of an abundance of caution, deep cleansing was conducted on the ship and in the terminal for the ship's turnaround in Brisbane today resulting in a slight delay in the ship's scheduled departure".
Colleen Barnett, a passenger onboard the passenger ship, told Yahoo Australia: "Everyone was told to take precautions, including washing their hands".
'We have been advised that on-board testing has found norovirus to be the cause of the illness'.
Health authorities in Queensland, Australia, confirmed that there were 'at least 91 cases of gastro [gastroenteritis]' on the ship, which docked in the city of Brisbane on Thursday.
Nausea, vomiting, diarrhoea and some stomach cramps are among the symptoms of norovirus.
It comes after 140 passengers came down with gastro in February after a Sun Princess cruise returned from a 14-day trip around New Zealand.
It is extremely contagious, which is why it is so important for cruise ships to catch the virus quickly.
Anyone who has had the bug should stay out of contact with people for up to 48 hours.