A criminal investigation is to be launched into the disastrous handling of the Ruby Princess cruise ship, which has become the single largest source of Covid-19 cases in Australia, the NSW police commissioner said on Sunday. Commissioner Mike Fuller announced the move as it was revealed four more passengers from the ill-fated ship have died – bringing the total number up to 11, and accounting for more than 30% of all Australian Covid-19 deaths. The Ruby Princess has been the focus of intense criticism since its 2,700 passengers were allowed to freely disembark in Sydney on 19 March, despite passengers on board showing signs of respiratory illnesses, and some being transported to hospital with Covid-19 like symptoms. The ship has since proven to be a hotbed of infection. At least 662 people linked to the cruise have been diagnosed with Covid-19, more than 10% of Australia’s total cases. In the weeks since it docked, state and federal government bodies have pinballed blame, with no agency taken responsibility for the ship handling. In a press conference today, Fuller focused his comments on the behaviour of the Carnival Cruise company. “The only way I can get to the bottom of whether our national biosecurity laws and our state laws were broken is through a criminal investigation,” he said. “The key question that remains unanswered … was Carnival transparent in contextualising the true patient and crew health conditions relevant to Covid-19? “There seems to be absolute discrepancies between the information provided by Carnival and what I would see is the benchmark for the laws that the federal government and the state government put in place in terms of protecting Australians from cruise ships when coronavirus had started.” Fuller also praised the NSW Port Authority for their efforts the night before the ship docked. “The New South Wales Port Authority did an exceptional job in trying to get to the bottom of the facts in relation to this case. They made contact with the ship on numerous occasions. They actually stopped the ship from coming into Sydney harbour without further medical information, they made contact with operations manager from Carnival. And on each case they were informed that Covid-19 wasn’t an issue on the ship.” Fuller did not rule out the possibility of criminal negligence charges being laid in relations to the case. He also confirmed around 200 crew members on board are currently showing symptoms of Covid-19, as medical officers continue to conduct testing. The Ruby Princess will remain in Australian waters, treating crew members in their medical facilities, and delivering those who require additional medical care to shore. Emails said to be from a crew member of the Ruby Princess were posted on a cruise blog run by a Miami based lawyer, Jim Walker. “The crew is sick and getting sicker,” read the email, which Walker says was sent at the end of March. “No idea how many actually have Covid but many have symptoms including lack of taste & smell.” The Sunday Telegraph reported that on the night the Ruby Princess docked, NSW ambulance operators were told that several passengers who required transportation to hospital had been tested for Covid-19 and results were still unknown. They claim this prompted port authorities to deny the ship permission to dock, however a representative from Carnival later allegedly called to say that the ambulance has not been called due to Covid-19 concerns, and the ship was allowed into Circular Quay. NSW Health has previously stated that although the passengers who were transported from the ship to hospital had flu-like symptoms, ambulances were called due to other medical conditions, such as lower back pain and heart problems. One of these patients, a woman in her 70s, died five days later of Covid-19 related illnesses. Since the ship’s 2,700 passengers were allowed to freely disembark in Sydney on 19 March, federal and state authorities have been pinballing blame. The possibility of cruise ship companies misleading authorities was also raised by the home affairs minister, Peter Dutton, earlier this week. “It’s clear that some of the companies have been lying about the situation of the health of passengers and crew on board, so what we’ve agreed to do with NSW is to look at each of the vessels,” he told 2GB radio. 50 days prior to the Ruby Princess docking, emails obtained by Guardian Australia show MUA assistant secretary Paul Garrett warning the NSW Port Authority that ship crews could not be relied upon to diagnose Covid-19 cases or accurately self-report illnesses. It was described by him as a “gaping hole in Australia’s biosecurity network”. NSW Health has also defended its actions, saying that although it was aware of 104 acute respiratory infections on board, they considered the ship to be “low risk” for carrying Covid-19. The NSW chief health officer, Dr Kerry Chant, said that if NSW Health had known that coronavirus was on board the ship, would have moved all passengers directly to self-isolation. However, she said that would have only prevented 11 known cases of the virus that were subsequently spread within the community. Previously a spokesperson for Princess Cruises said of the 19 March arrival: “Our onboard medical team was rigorous in its treatment of some guests who reported flu-like symptoms, and these guests were isolated. “The ship reported these cases to NSW Health, which in turn requested swabs to be provided following the ship’s arrival in Sydney, some of which subsequently tested positive for Covid-19.” On Sunday evening a spokesman for the company responded to the announcement of a criminal investigation. “We have seen the Police Commissioner’s announcement,” he said. “In addition to willingly participating in the investigation, Carnival Australia will vigorously respond to any allegations of which there must now be full disclosure and the basis for them.” All deaths related to the Ruby Princess have been passengers, and not those who contracted the disease through community transmission. While it appears that the Ruby Princess will not be asked to leave Australian waters in the near future, there is still a concern for the crews of five other cruise ships that departed Australian waters over the weekend. These include the Celebrity Solstice, Voyager, Ovation, Spectrum and Radiance of the Seas.