A class action is being prepared against Carnival Cruises after hundreds of passengers on the Ruby Princess became infected with Covid-19 and 10 people died.
The ship visited a number of New Zealand ports during its cruise and despite an outbreak of illness, those on board were allowed on shore.
Shine Lawyers in Australia is behind the class action.
It said the passengers were not advised of the risk and were not monitored for symptoms.
The class action was open to all passengers who were on board the ship, as well as people with links to it, Shine Lawyers said.
It said it was exploring whether it could hold the cruise ship owners, including Carnival, to account for failing to protect its passengers.
The lawyers say that despite the ship previously logging 158 cases of illness, the 2700 passengers were not told and they were then allowed to disembark and return to their homes.
- If you have symptoms of the coronavirus, call the NZ Covid-19 Healthline on 0800 358 5453 (+64 9 358 5453 for international SIMs) or call your GP - don't show up at a medical centre
New Zealand connections
A Wellington woman, Janice, said Ruby Princess passengers freely wandered the streets when it docked in the capital last month.
"We were taking two of our grandchildren out - we were on the Cable Car with Ruby Princess passengers - we were at the Cable Car museum with lots more of them," she said.
"My daughter and another grandchild were at a Festival of the Arts performance that morning, for over an hour in the Soundings Theatre at Te Papa.
"At the last minute, a person off the Ruby Princess sat next to them for the whole performance. They know because they were chatting.
"I told Healthline this and there was no interest in a followup basically because the Ruby Princess flew under officials' radar for too long.
"We are all now way past the incubation period and fine but this had the potential to be serious for our families."
She said Carnival Cruises needed to accept responsibility for allowing passengers off.
"We seem to have been okay - we don't seem to have got anything - I twice rang Healthline but they didn't think that it was necessary to get tested," she said.
In Hawke's Bay, a cluster of 16 people with links to the Ruby Princess were recovering from the virus.
Director General of Health Ashley Bloomfield said they were in a couple of groups.
"There are six people who were passengers on the ship and have come back into New Zealand from Australia, secondly there are four people who were either a van driver, or a tour guide, and one was a translator who picked up the infection during its final stop in New Zealand," Dr Bloomfield said.
"And there is another infection associated with one of those people in a aged residential care facility - and that is where there is the other six," he said.
The cruise ship departed Circular Quay in Sydney on 8 March for an 11-day cruise around New Zealand, before docking in Sydney again on the 19th.
Nearly 3000 passengers and crew were on board and more than 600 people have tested positive for the virus.
Ten people connected with the ship have died in Australia.
Criminal investigation in Australia
The New South Wales government has ordered a criminal investigation.
The state's police commissioner, Mick Fuller, said that should get the bottom of whether laws were broken.
"Well there seems to be absolute discrepancies between the information provided by Carnival and what I would see is the benchmark for the laws of the federal government and the state government put in place in terms of protecting Australians from cruise ships when coronavirus had started," he said.
Carnival Cruises did not want to be interviewed.
It said in a brief one line response that it would not be commenting on the class action.
Read more about the Covid-19 coronavirus:
- See all RNZ Covid-19 news
- A timeline: How the coronavirus started, spread and stalled life in New Zealand
- Covid-19 symptoms: What they are and how they make you feel
- Touching your Face: Why do we do it and how to stop
- Scientific hand-washing advice to avoid infection
- Coronavirus: A glossary of terms
- The Coronavirus Podcast