Ruby Princess’s docked and disembarked passengers on 19 March, but the vessel has since been linked to a number of coronavirus cases – and deaths – across Australia.

Earlier this week, New South Wales police commissioner Mick Fuller announced a criminal investigation into the "communications, actions, and other circumstances that led to the docking and disembarking of the vessel at Sydney Harbour".

The force confirmed on Thursday (9 April) detectives were new conducting inquiries onboard the ship as part of the investigation.

At around 7pm on Wednesday (8 April), strike force detectives boarded the ship to conduct inquiries, which included speaking with crew members, as well as gathering and seizing the voyage data recorder, or black box, and other items of interest to the investigation.

Fuller, The Guardian reports, said the detectives onboard Ruby Princess were gathering evidence about why the ship was allowed to dock and hundreds of passengers to disembark in spite of concerns about Covid-19 cases.

More than 1,000 members of crew remain onboard, and will undergo medical assessment, with "about 200" showing mild symptoms of the infection and 18 testing positive.

Australian Border Force commissioner Michael Outram said those showing symptoms would be isolated onboard, while those "particularly ill" would be disembarked and treated on land.

An investigation into which body gave the ship authorisation to dock and disembark is also under way.

A Carnival Australia spokesperson said: “The Voyage Data Recorder’s sole purpose is recording navigational information and radio transmissions to and from a port’s control centre for use in marine accident investigations.

"It has no bearing on the health clearance process that Ruby Princess followed to the letter.”