The Dawn Princess liner, with 1996 passengers on board, was not allowed to stop on the island of Lifou in New Caledonia early today after four or five people on board presented with flu-like symptoms.

Carnival Australia spokesman Anthony Fisk said the ship was on a 13-day cruise of the South Pacific and was due to make its final stop on Lifou Island in New Caledonia before returning to Sydney on Friday.

But when four or five people reported to the ship's doctors with flu-like symptoms, the crew followed procedure and notified New Caledonian authorities.

"The New Caledonian officials asked us not to come into port today," Mr Fisk said.

"We're under the jurisdiction of New Caledonia and we respect their decision.

"We notify health authorities of all flu instances ... we're aware of the widespread concern regarding individuals with the flu."

It was not yet known exactly how many people were being tested or whether they were passengers or crew, he said.

The ship dispatched a crew member with the four or five swabs. They were flown off Lifou today and would be tested in Sydney, Mr Fisk said.

"The results will be available before we get into port again," he said.

It is the second cruise liner to be intercepted amid swine flu fears after the Pacific Dawn spent two weeks in quarantine while its 2000 passengers were tested for the influenza strain. All on board returned negative results.

The Dawn Princess left Sydney nine hours late on May 24 after two passengers on the previous cruise needed testing for swine flu. Their results were also negative.

The current cruise was due to leave at 4pm on May 23 but was delayed until 1.30am on May 24.

It missed its first scheduled stop in New Caledonia, on the island of Noumea, because of bad weather, Mr Fisk said.

It then stopped three times in Fiji and once in Vanuatu. The ABC's Radio Australia reported Fijian authorities set up health checks to screen the Dawn Princess's passengers when they disembarked there on May 28.