A Carnival cruiseship at the centre of a row over the spread of coronavirus in Australia has berthed at Port Kembla.

However, the crew on the 113,500-gt Ruby Princess (built 2008) will not be allowed to disembark, the New South Wales (NSW) Police Force said.

Up to 200 of the 1,040 crew members on board the vessel at Port Kembla, about 75 km south of Sydney, are said to be displaying symptoms of Covid-19, while 16 have tested positive.

The Ruby Princess came alongside on Monday to allow for “safer access for medical assessments, treatment or emergency extractions of her crew”, the authorities said.

“It is believed the vessel may remain in place for up to 10 days, but the crew will not disembark unless in an emergency and approved by the NSW police commissioner,” the police said.

The ship will be refuelling and restocking provisions, “as required for her home journey”.

Police commissioner Mick Fuller has launched a criminal investigation. Photo: NSW Police Force

NSW Police said the berthing will be conducted under “strict health and biosecurity guidelines” and will not “pose a risk to employees at the port or the broader community”.

On Sunday, authorities launched an investigation into the circumstances surrounding the docking and disembarking of the Ruby Princess in Sydney on 19 March.

State police commissioner Mick Fuller said a “criminal investigation is now underway” to “fully examine the communications, actions and other circumstances” that led to the docking and disembarkation.

More than 600 people on board the Ruby Princess later tested positive for coronavirus and 10 have since died.

Thousands of witnesses

The investigation is expected to involve interviewing “thousands of witnesses”, including the ship’s captain and doctors, the crew and passengers.

“I’ve examined a number of phone calls between NSW Ambulance, Port Authority of NSW and NSW Police that stemmed from the initial 17-minute triple zero [emergency] call from the ship to NSW Ambulance on 18 March,” Fuller said.

“There appears to have been an exceptional amount of effort put in by ports to determine the true nature of the conditions on board — and [they] even delayed the vessel's arrival until they were provided additional information.

“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.”

Investigators will “examine the actions of everyone involved”, whether from the cruise company or government agencies.

“This is a complex issue and we will need information from many witnesses to answer all the questions about how this ship ended up docking last month,” Fuller said.