Over 600 cases and 15 deaths have been linked to the ship, according to public broadcaster ABC.
New South Wales police commissioner Mick Fuller said Wednesday that the ship’s captain was “extremely helpful,” and that the black box, a recorder similar to that found on airplanes, was recovered along with other evidence.
Officers went on the ship under the powers of the NSW coroner who has started a preliminary investigation.
It is expected that the investigation will involve interviewing thousands of witnesses, including the ship’s captain, doctors, crew members, and passengers, and officials from the federal and state government.
“After reviewing the information at hand, the only way I can determine whether our national biosecurity laws or our state laws were broken is through a criminal investigation,” Fuller said last week.
That investigation is running alongside the probe being conducted under the auspices of the coroner’s office.
Fuller said Wednesday police were waiting for a human health report before deciding next steps and that report would be central to the investigation. He could not give a time frame for the investigation.
More than 1,000 crew members remain on the ship and Fuller says 75% have said they’d like to remain on the ship.
Australia’s Department of Foreign Affairs and Trade said this month it was in direct contact with 10 cruise ships with around 600 Australian passengers on board.
“In most cases, disembarkation cannot occur unless passengers have onward flight arrangements and are able to travel directly to the airport via a so-called sanitary corridor, put in place by host countries,” DFAT said in a statement.
CNN’s James Griffiths contributed to this report.