You are more likely to be sexually assaulted on a cruise ship than on land, an expert in ship safety will tell a conference in Auckland this week.
Professor Ross Klein, a sociologist from Canada's University of Newfoundland, told AAP people wrongly assumed cruises were completely safe, and it was mostly crew members who were to blame for attacks.
Looking at figures provided to a US court by a cruise line, he found 111 people per 100,000 were sexually assaulted on ships.
He said his figures showed people were 50% more likely to be sexually assaulted on a ship than on land.
"If you were to go to the Cruise Lines International Association they will say that a cruise is the most safe form of transportation. That is now getting a bit of scrutiny," he said.
"In the early 80s there was a case where two crew members tried raping a passenger and she died by accident, supposedly. They were caught throwing her body overboard as they were leaving the harbour," he said.
He said the shocking case of Australian woman Dianne Brimble, who was found dead and lying naked on a cruise ship cabin floor after ingesting a lethal mix of alcohol and the illicit drug fantasy, was not a one-off.
"I think these events happen and the industry has learned very well how to cover these things up, or at least keep them under wraps.
"The guys involved in the Brimble case give us some good insights. As I recall one of them said `after she died we wanted to throw her body overboard but we couldn't find any way to get her body up to the top deck without being seen'," Klein said.
He said parents should keep an eye on children they take onto cruises.
"You have to go on assuming a cruise is no safer than any other form of transportation, and you take the exact same precautions, if not more precautions as you would take going into any city," he said.
"Parents whose children were sexually molested will often say `the cruise line told me it was safe. I thought it was OK for my children to run around free without supervision'."
He said about 80% of sexual assaults on cruises were carried out by staff.
Klein will on Thursday address the Coastal and Marine Tourism Congress in Auckland.
A statement from the P&O Cruises later said Klein had used inaccurate figures.
"Professor Klein has used figures that are not an accurate representation of P&O Cruises experience in Australia and New Zealand, where we carry more than 100,000 passengers each year," it said.
"Prof Klein appears to have taken figures from one cruise line in the US and then extrapolated them across all cruise companies and markets.
"The figures he has come up with do not match our passengers' experience and cannot be applied to P&O Cruises."
Since at least May 2005, no crew member or passenger had been charged with sexual assault while on one of their vessels, it said.
The company said it had introduced many changes to its operations since 2005, especially in passenger service, safety and security.
"Those changes, which accelerated after the start of the inquest into the tragic death of Mrs Brimble, were described by counsel assisting the coroner as a complete reform of the cruise industry insofar as P&O is concerned," it said.
"We have put in place a range of safeguards to try to ensure what happened to Mrs Brimble cannot happen again and we will continue this commitment."
