A passenger that tested positive for COVID-19 aboard Quantum of the Seas on her third cruise from Singapore after returning to service has now tested negative twice, according to the Singapore Health Ministry.

An 83-year-old passenger tested positive aboard the cruise ship while she was cruising roundtrip from Singapore, forcing the cruise line to cancel the voyage and return to port, with the ship’s COVID-19 outbreak prevention plan fully in place.

Quantum of the Seas alongside at the Marina Bay terminal in Singapore.

RELATED: Odyssey of the Seas floated out for Royal Caribbean ahead of US debut in 2021

RELATED: Limited cruise resumption slightly softens $1.2-billion Q3 loss for Royal Caribbean

All passengers were isolated, while the infected passenger’s close contacts underwent further testing, which also turned back negative results.

Passengers have now begun to disembark the ship, but Royal Caribbean has cancelled her next cruise out of what it calls an abundance of caution.

Guests will be required to monitor their health for the next two weeks and will be required to have a COVID-19 swab test at the end of the 14-day period. The test will be arranged by Royal Caribbean.

Quantum of the Seas earlier this month resumed cruise operations from Singapore’s Marina Bay terminal under a set of strict health and safety protocols developed between Royal Caribbean Group and the Singapore Tourism Board.

She is the first of the cruise line’s vessels to return to service.

The 4,100-guest ship’s capacity has been restricted to a maximum of 50 percent and bookings are only open to Singaporean residents.

Quantum of the Seas was temporarily quarantined.

RELATED: Refurbished Quantum of the Seas to homeport in Singapore for longer

RELATED: Keel laid for Royal Caribbean’s 2nd Quantum-Ultra, Odyssey of the Seas

When the suspected COVID-19 case was announced during the night on the ship’s third day out of Singapore, all guests were asked to isolate in their staterooms, prompting concerns of a repeat of the extended quarantine of Diamond Princess and Grand Princess earlier this year.

However, guests have now been allowed to disembark following the results of their coronavirus tests. The quarantine procedure is in line with what is expected to happen if cruising were to resume in the United States.

Quantum of the Seas is one of only two cruise ships currently sailing from Singapore. Genting Cruise Lines’ Dream Cruises brand has operated out of Singapore since November without incident.

Quantum of the Seas only had 1,093 guests on her first sailing, but there were 1,680 guests and 1,148 crew aboard the ship during her affected cruise.

Royal Caribbean will offer a pro-rated cash refund for the day missed at sea, and any remaining onboard credits will be refunded to guests. The cruise line will also provide a day of Future Cruise Credit for use on a future sailing.