Shine Lawyers on Friday announced a class action against Carnival Plc and Princess Cruise Lines Ltd over their handling of COVID-19 cases on the ship, which disembarked in Sydney on March 19.

The law firm is seeking compensation through the federal court on behalf of passengers and their families.

It comes as a NSW special commission of inquiry examines the circumstances surrounding the cruise, which has been linked to hundreds of cases and more than 20 coronavirus-related deaths across Australia.

Vicky Antzoulatos from Shine Lawyers said the class action would allege the defendants breached consumer guarantees, engaged in misleading and deceptive conduct and failed in their duty of care to provide a safe cruise.

"We say the owner and operator knew of the risks that passengers may contract coronavirus before the ship left and they failed to take steps to ensure their passengers were safe and protected," Ms Antzoulatos said in a statement on Friday.

"People on board the ship trusted Carnival to do the right thing but they were not told about the risk of coronavirus and some paid the ultimate price for it."

Class action group member Graeme Lake's wife Karla died from coronavirus 10 days after returning home from the cruise.

"It broke me, it broke the kids, and she didn't deserve it," Mr Lake said in the same statement.

"Karla went on that cruise to celebrate her 75th birthday and what happened to her has destroyed us."

Princess Cruises in a statement on Friday said they had "the utmost respect for our guests and understand the worldwide impact of COVID-19 including on some of our guests, crew members and their families".

"The NSW special commission of inquiry, in which we are participating, is in the process of establishing the facts in relation to Ruby Princess. It is not our intention to respond to the assertions of class action lawyers," the company said.

The special commission of inquiry has concluded and is set to report back by mid-August.

Australian Associated Press