Editor's Note: National Disaster Management Agency had erroneously named the US embassy in Malaysia as the charterer of four Malaysia Airlines. It has since issued a correction to say the charterer is Holland America Line. This report has been updated to reflect the correction.   

A second test on an 83-year-old US woman who Malaysian health authorities say is infected with Covid-19 has returned as positive again.

This comes as the last batch of the cruise passengers who were on board with her on the MS Westerdam, which docked in Cambodia on Feb 13, leave the ship.

Upon docking at Sihanoukville, Cambodia, the woman and 144 other passengers were flown into Malaysia on Feb 14 on a Malaysia Airlines flight chartered by the cruise ship owner Holland America Line to help them return home.

The cruise ship owner, Seattle-based Holland America Line, had earlier today maintained that none of its passengers had shown Covid-19 symptoms and said the test by Malaysian health authorities was still at the preliminary stage.

"While the first results have been reported, they are preliminary at this point and we are awaiting secondary testing for confirmation," it said.

All 145 passengers on board the flight were screened upon arrival at Kuala Lumpur International Airport and two had shown Covid-19 symptoms, the 83-year-old woman and her 85-year-old husband.

Tests results, which returned on Feb 15, showed the 83-year-old to be positive with Covid-19 while her husband tested negative.

Deputy Prime Minister Wan Azizah Wan Ismail today said a repeat test yielded the same outcome.

"A repeat test for Covid-19 was conducted on the husband-wife pair late last night yielded the same results - positive for the wife and negative for the husband," she said in a statement.

The ship initially had 1,544 passengers and 802 crew members. The disembarkation process was done in phases as they were asked to complete a written health questionnaire.

"MS Westerdam is alongside in Sihanoukville, Cambodia, with 236 guests and 747 crew on board. The remainder of guests from the voyage departed Sihanoukville via charter flights to Phnom Penh yesterday and today and are in various stages of transit home," said Holland America Line.

"The passports of everyone on board were reviewed to ensure no one had travelled through mainland China in the prior 14 days," said the cruise firm.

Cambodian health authorities had initially cleared the passengers of the disease. 

In light of the development, Malaysia Airlines has cancelled the remaining three flights chartered by the cruise ship owner to bring the passengers home via Malaysia.

For the record, Sihanouk International Airport does not have any direct flights to Europe or the US.

The octogenarian patient is under observation at the isolation ward at Sungai Buloh Hospital and is accompanied by her husband.

She is Malaysia's 22nd Covid-19 case. No deaths have been reported to date while eight have fully recovered.

As for the remaining 143 passengers who have all been screened, 137 have continued on to their next destination while six more are still waiting for connecting flights to their respective destinations.

Wan Azizah (above), however, said Malaysia will still test the six for the Covid-19 and will allow them to proceed if the results come back negative.

Malaysia has informed Cambodian health authorities of its findings and also alerted health authorities of the countries where passengers are travelling to for tracking purposes, she said. 

The virus, which first broke out in Wuhan, China, has infected 69,264 people to date with 1,669 deaths.

At an estimated fatality rate of 2 percent, the Covid-19 is less deadly than the Severe Acute Respiratory Syndrome (Sars) which infected 8,098 people and killed 774 people in 17 countries between 2002 and 2003, representing a fatality rate of around 9.6 percent.

However, Covid-19 is more infectious than Sars and this has contributed to more total deaths.