A woman from Macau is reportedly suffering from a fever and breathing difficulties

Medical sources said that it was “unlikely” that the couple from Macau had the potentially deadly virus but all precautions were being taken.

An unknown number of Australian's are onboard.

The ship was put on lockdown when it was noticed that the 54-year-old wife was suffering from a fever and breathing difficulties.

Authorities said passengers and crew would be held on the vessel, which is docked in the port of Civitavecchia north of Rome, until the all-clear was officially given.

That could take up to 48 hours, according to the doctors from the Lazzaro Spallanzani national institute for infectious diseases, who were conducting the tests.

The two Chinese tourists were placed in isolation in the ship’s hospital.

There were reportedly more than 700 other Chinese passengers on board but they were reportedly in good health.

The Macau couple arrived in Italy on January 25 and boarded the ship in the port of Savona that same day, a spokesman for the Costa Crociere cruise company said. 

The ship visited Marseilles, Barcelona and Palma de Mallorca before docking on Thursday at Civitavecchia, north of Rome.

Photos on social media showed passengers, with their bags packed, looking fed up on board the ship.

"We arrived in [Civitavecchia] with the Costa Smeralda cruise ship and they are not letting us off the boat. They say it's due to a health inspection," a passenger named Gaby tweeted.

Adriano Pavan, whose son and two grandchildren were on board and who had travelled to Civitavecchia to meet them off the ship, told Agence France Presse that he was "quite worried".

"My son told me the Chinese couple had been wearing masks for the past two or three days, but they thought nothing of it".

Earlier on Friday there was a plan to allow 1,143 passengers, whose cruise was due to end in Civitavecchia, to disembark.

But the mayor of the city strongly objected, saying he had “expressly requested” that passengers and crew be kept on the ship until definitive medical results were known.

According to Italian media reports, Ernesto Tedesco raced to the dockside in his Fiat 500 and yelled at officials: “Are you mad? Who gave you the order to disembark? I'll take you all to court.”

Civitevecchia is a few miles down the coast from the island of Giglio, where the Costa Concordia capsized in 2012 with the loss of 32 lives.

Cruise Ship Coronavirus Trouble In The Phillipines:

Another cruise ship, the 'Westerdam' is stuck in South China Sea because of Philippines coronavirus ban.

An Adelaide couple is among up to 2,000 people stuck on a cruise ship in the South China Sea after it was refused entry to the Philippines because of fears about the coronavirus.

Philippines President Rodrigo Duterte yesterday temporarily banned travellers from China, Hong Kong and Macau disembarking in the country after recording the first death from coronavirus outside of China.

Holland America's cruise ship Westerdam left Hong Kong on Saturday after a six-hour stay, but about 24 hours into its trip to Manila the captain announced it would not be allowed into the Philippines.

"My wife and I were at dinner and I said 'the boat's slowed down'," Mr Holst told ABC Radio Adelaide.

"It obviously was and then a little while later an announcement came over the PA saying Manila has denied us entry."

Hong Kong is not subject to the same strict travel restrictions as China.

Mr and Mrs Holst were about halfway through a 30-day cruise through Asia, starting in Singapore and ending in Shanghai.