A suspected case of Covid-19 on a Singapore "cruise to nowhere" has been thrown into confusion after a subsequent test on the patient proved negative.

Royal Caribbean International’s 169,000-dwt Quantum of the Seas (built 2014) was forced to cut short a four-day cruise due to the incident.

However, late on Wednesday, Singapore’s ministry of health (MOH) said that two subsequent tests of the patient had produced negative results.

“An 83-year-old male Singaporean on board Royal Caribbean International’s Quantum of the Seas tested positive for Covid-19 infection … and was immediately isolated,” MOH said.

“He had reported to the medical centre with diarrhoea, and, as part of the protocols, was tested for Covid-19 using the polymerase chain reaction test equipment on board the ship.

“His original sample has since been retested at the National Public Health Laboratory [NPHL], and has come back negative for Covid-19 infection. A second fresh sample tested by NPHL has also come back negative.”

The MOH said NPHL will conduct another test on Thursday to confirm his Covid-19 status.

Precautionary measure

In the meantime, it said all of the identified close contacts of the case have been isolated as a precautionary measure.

“As part of the routine post-arrival protocols, all passengers underwent mandatory Covid-19 testing before they are allowed to leave the terminal at Marina Bay Cruise Centre,” it added.

Royal Caribbean said the ship will be deep cleaned and disinfected and the cruise scheduled for Thursday will be cancelled.

"Being able to identify this single case and act on it immediately demonstrates the system is working as it is designed to," it added.

Genting Cruise Lines, which has also started cruise to nowhere voyages out of Singapore said sailings of its 150,600-gt World Dream (built 2017) would “continue as scheduled”.

Singapore, which has reported just over 58,000 Covid-19 cases and 29 deaths, has barely seen any new local infections in recent weeks.

The city state has been piloting the cruise to nowhere concept, which is open only to residents, makes no stops and sails in waters just off the island.

The initial cruises where well subscribed due to pent-up demand from Singaporeans who have been living under Covid-19 restrictions since April.