A passenger aboard a cruise ship that docked in Sydney Harbour early on Friday morning has been tested for coronavirus.

NSW Health authorities boarded the Norwegian Jewel after it docked in Sydney from Auckland on Friday with more than 2000 people on board.

The extra precautions were in accordance with new security protocols to protect against the potential spread of the deadly COVID-19.

The extra testing delayed passengers’ disembarking for at least an hour.

One passenger Ces Tuason posted on social media: “Originally scheduled at 8.15am but given go signal to disembark at 9.00am. Currently touring the city now in our rented van”.

Earlier on Friday, The Australian reported Norwegian Jewel was in lockdown after a male passenger fell ill with respiratory symptoms and was being checked. That report was later amended.

The ship’s operator, Norwegian Cruise Line, denied there was any truth to the report, but admitted some guests were suffering stomach illnesses.

1/ Well that had to be the worse cruise I've ever had. Part way through I developed vomiting and diarrhea. Wife had severe motion sickness, got off 1/2way through and flew home. Next day got whatever I had and is still affected by it 3 days later @CruiseNorwegian #NorwegianJewel

— Tony 🇦🇺🇺🇦 (@tonka9754) February 13, 2020

Health authorities, meanwhile, said there was no risk to the public.

“At this point there is no concern for other passengers or people in and around Circular Quay,” NSW Health said in a statement.

Norwegian Cruise Line said the vessel, which was scheduled to depart later on Friday for a 14-day cruise of Australia and New Zealand remained in operation and was not in lockdown.

The company earlier said all inbound passengers were healthy but later revised its statement on Friday to confirm some passengers had come down with stomach illness while sailing from Auckland to Sydney.

However, no passengers had respiratory-related illnesses, it said.

“To mitigate any impact of this rare occurrence, we implemented stringent sanitation procedures. As such, upon the ship’s return to Sydney on Friday, February 14, 2020, a thorough inspection and rigorous cleaning and disinfection of the ship and terminal were conducted,” a spokeswoman said in a statement.

“There are various false inflammatory media reports regarding the ship.

“There is absolutely no truth to those stories.”

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NSW Health said no Norwegian Jewel passengers had visited mainland China in the past fortnight.

There were three “routine” medical transfers from the ship on Friday, with none related to respiratory illness.

NSW Health confirmed one person had been tested for respiratory illness onboard, but said that was a precautionary measure. Test results later cleared the passenger of having the virus.

“As cruise ships have large number of passengers (often thousands), many of whom are older and have chronic medical conditions, passengers often require medical management while on the cruise or on disembarkation unrelated to infectious diseases,” a NSW Health spokeswoman said.

Norwegian Cruise Line has barred all Chinese, Hong Kong and Macau passport holders from its ships, regardless of residency.

Worldwide, there are more than 60,000 confirmed cases of COVID-19, most of them in the Chinese province of Hubei where it was first detected, and 1357 people have died.

Of the 15 cases in Australia, six have been cleared and the remaining nine are all stable.

-with AAP