SINGAPORE: A Genting Cruise Lines' ship on a "cruise to nowhere" has returned to Singapore after a passenger was suspected of having contracted COVID-19 and the nearly 3,000 passengers and crew on board have been confined to their cabins.

A 40-year-old passenger tested positive to a Polymerase Chain Reaction (PCR) test onboard and had been conveyed to hospital for further testing after the ship docked early on Wednesday, the Singapore Tourism Board said.

"The passenger was identified as a close contact of a confirmed case on land, and was immediately isolated as part of onboard health protocols," the board said in a statement.

The global cruise industry has taken a major hit from the coronavirus pandemic, with some of the earliest big outbreaks on cruise ships in Asian waters.

Singapore, which has seen relatively few domestic COVID-19 cases, launched "round trips" on luxury liners in November, with no port of call during a few days of sailing.

Dream Cruises' World Dream had 1,646 passengers and 1,249 crew members on board and all of them were required to remain in their staterooms with contactless meals sent to them, Dream Cruises, a part of Genting Cruise Lines, said.

The guest suspected of having COVID-19 had tested negative in a mandatory, pre-departure antigen rapid test before the ship set sail for a three-night cruise on Sunday.

The passenger's three travelling companions tested negative and were isolated while further contact tracing was being done, the tourism board said.

Only essential service crew with personal protective equipment were being allowed limited movement within the ship, Dream Cruises said.

Passengers said they found out about the suspected case in an announcement at around 1:00 a.m.

"We were prepared for the possibility," said passenger Suryana Ali in an online session with media organised by the operator.

Several guests on board the docked ship could be seen chatting to one another across their private balconies, a Reuters witness on Singapore's waterfront said.

The cruises to nowhere, restricted to Singapore residents, have become popular during the pandemic with very limited other travel opportunities because of coronavirus restrictions.

Tan Choon Seng, 51, was on his third cruise this year with some friends when the bad news came through, but at least it was nearly the end of the holiday, he said.

"We are thankful that this happened at 1 a.m so we were done with all the activities," Tan said.

Tan said he was worried about quarantine but would go on a cruise again.

The passengers said they were waiting to be told when they could disembark.

World Dream's next sailing, a two-night voyage departing on Wednesday, has been cancelled.

In December, passengers on Royal Caribbean's Quantum of the Seas vessel were held in their cabins for more than 16 hours in Singapore after a suspected COVID-19 case on board.

But that turned out to be a false alarm.