Health officials in Australia say they are considering quarantining a cruise ship carrying 2,000 passengers after three crew members were found to have the H1N1 flu virus.

The Pacific Dawn will now cut short a voyage to marine attractions in the state of Queensland and is on its way to an unspecified major Australian port.

Nicola Roxon, Australia's health minister, said on Thursday the ship is ready to be quarantined in order to limit the spread of the virus.

"Certainly there will be no hesitation from our government or from the states and territories to take the advice of the health officials if they thought that was necessary," she told local radio.

The Pacific Dawn has already been blamed for an increase in flu cases after authorities last week allowed all the passengers to leave the ship in Sydney despite a suspected outbreak on board.

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"We are working very hard to contain this," Roxon told reporters in the capital Canberra after the confirmed number of cases jumped from 61 on Wednesday.

Health experts meanwhile have warned that Australia's rapidly rising number of flu cases could become an epidemic affecting up to 25 per cent of the population.

'Flu season'
 

There is growing alarm in Australia over the rapid rise of H1N1 flu cases [EPA]

Roxon said the government would also buy a further 1.6 million courses of Relenza, an antiviral drug to bolster the national stockpile to 10.3 million courses.

Most cases of H1N1 flu were located in the country's most populous states of New South Wales and Victoria, which are heading into the winter season.

The supply would cover just less than half of Australia's 21 million people, but Roxon said medical authorities would prioritise which areas and people would most need the vaccine.

According to the World Health Organisation, the number of H1N1 cases has soared to nearly 13,400 case in 48 countries, with 100 deaths.