The Ruby Princess cruise ship will now be the subject of a special commission of inquiry, as well as a criminal investigation.
NSW Premier Gladys Berejiklian has appointed Sydney silk Bret Walker — who successfully appealed against George Pell's conviction in the High Court — to conduct the inquiry.
The barrister will be given "extraordinary powers" to investigate all matters and agencies involved with the Ruby Princess' departure and its return to Circular Quay on March 19.
On that day, 2,700 passengers were allowed to disembark despite some showing symptoms of, and being swabbed for, coronavirus.
Their test results had not yet been received when the passengers were allowed off the boat.
State and federal health and border protection agencies, as well as the ship's management company, have been locked in a slanging match as to who is responsible for the debacle.
Eighteen passengers have died and hundreds of cases have been connected to the ship, including some who were infected by passengers in the community.
The inquiry will be expected to report back to the Premier in three to four months, while the criminal investigation will not conclude for another five months.
"It is important that answers are provided quickly for the people of NSW," Ms Berejiklian said.
"I have decided that the quickest path to answers is through a powerful and independent inquiry."
The Ruby Princess docked at Port Kembla a week ago and a private health company, Aspen Medical, was in charge of assessing care on the ship.
At least 128 crew on board have also tested positive to COVID-19.
There have been numerous evacuations of crew from the ship requiring emergency care in hospital.
The criminal investigation — launched last week — already has 220 leads.
Police suggested the starting point of the investigation was assessing whether the Ruby Princess and its operator, Carnival Cruises, were honest about the illness onboard.
They also indicated all passengers may be interviewed.
It is unclear whether public hearings will be held as part of the special commission of inquiry.
