A laboratory used to pre-screen passengers for a Qantas repatriation flight from India had its accreditation suspended by the nation’s laboratory board in April, the ABC has revealed.

And at least three of the Australians blocked from returning home on Saturday’s flight from New Delhi to Darwin, because they tested positive for COVID-19, have since tested negative for the virus.

The two revelations raise serious questions about the medical screening process set up by Qantas and the federal government for the resumption of travel between India and Australia.

CRL Diagnostics was used to conduct COVID tests on 150 “vulnerable” Australians who had been staying in a hotel as part of pre-flight quarantine measures.

The testing found 46 positive cases, meaning they and an additional 24 close contacts were barred from boarding the flight, which landed in Darwin on Saturday with only 80 people on board.

But CRL is no longer accredited by India’s National Accreditation Board for Testing and Calibration Laboratories (NABL) after it was suspended in April, according to the NABL website.

NABL chief executive N Venkateswaran said the suspension was for “non-compliance with NABL accreditation norms”.

“Suspension is temporary invalidation of accreditation and can be revoked,” he told the ABC.

“Due to confidentiality, we will not be able to say more than that the lab was found not complying with accreditation norms and hence suspended.”

Eighty repatriated Australians arrived in Darwin from India on Saturday morning, after almost half the flight was not allowed to board. Photo: AAP_ Royal Australian Air Force_Stewart Gould

CRL Diagnostics managing director Ravi Tomar told the ABC the suspension was for misusing the NABL logo. He said it was a “mistake” that was fixed and the company had appealed against the suspension.

Malini Aisola from the All India Drug Action Network said there was a lack of strong regulation of laboratories in India, and the NABL was a “voluntary” accreditation intended to ensure “quality” control.

“This is a moment when people are really depending on test results,” she said.

“We are in the middle of a massive surge and these [passenger] results are not reliable. This should not be tolerated.”

The company is, however, still registered with the Indian Council of Medical Research (ICMR), a national medical research body, to do COVID tests.

Pathologist Anan Jaiswal told the ABC the ICMR was a research institution and had “nothing to do with diagnostics”.

The ABC has surveyed 23 of the 46 would-be passengers who recorded a positive test with CRL and were subsequently forced to stay in New Delhi.

But as of Saturday, none had yet displayed any symptoms of COVID-19, and many told the ABC they were bewildered when they got the result.

Nineteen of them recorded a test with what experts regard as a “low viral load”, while four others have not yet been given their detailed results.

‘I’m not really sure what to believe anymore’

Questions have been raised as to how prospective passengers could have caught the virus while isolating. Photo: ADF

University of New South Wales epidemiologist Mary-Louise McLaws said the very close range of results – combined with the fact that few, if any, passengers appeared to be displaying any symptoms – raised a red flag.

“The range of the [testing results] are so similar, that I’d want another test to ensure that this wasn’t a lab error or a testing error, and ensure that in fact, they really are infectious,” she told the ABC.

Many passengers have also got their own tests in the wake of being bumped from the flight.

One passenger – Jatin Wig – said he was told on Friday that he and his family would be barred from going home because his wife and toddler had tested positive for COVID-19 at the hotel.

But the family immediately went and got a second test for his wife because neither she nor their child had felt at all unwell.

On Saturday they got the result, and it came back negative.

“This is crazy. I’m not really sure what to believe anymore,” he told the ABC.

“Obviously, there is something wrong with the initial tests, so many of them showed positive [results] and all of them [are] asymptomatic.”

He said he was “relieved” his wife was not sick, but deeply frustrated that he might have been prevented from returning to Australia for no good reason.

Jatin Wig and his family were barred from returning home because his wife and toddler had tested positive for COVID-19. Photo: ABC

Another prospective passenger, Priyanka, said she was sceptical when she was told her elderly father – who was also due to get on the flight to Darwin – had tested positive to COVID-19.

“We had our doubts in our mind. So rather than going home, he straight away went to the testing centre, the same provider which had done the testing [for the flight] and he got himself tested,” she said.

“We just now we have received the result that he’s negative.”

She said the confusion and uncertainty had taken a toll on the whole family.

“I can’t tell you the emotions we have been going through,” she said.

“My mother is 70-plus, and she hasn’t eaten the whole day thinking that my dad has tested positive.”

Passengers also complained to the ABC that the results showed grossly inaccurate testing times, as well as individual cases where the wrong age or sex was listed.

The ABC put the complaints about testing to Mr Tomar and he responded by saying that another company was responsible for working with the data.

Epidemiologist questions pre-flight testing process

Passengers coming back from India on repatriation flights in the wake of the government’s brief Indian travel ban must undergo and return a negative result on two tests before they get on the plane — a PCR test in the two days beforehand and then a rapid antigen test.

That process was agreed to by the federal government and Qantas in order to protect both airline staff and to reduce the risk of overwhelming Australia’s quarantine system with new COVID-19 cases.

Under the testing regime, those who registered any sort of positive result under the PCR test were then immediately bumped from the flight, and were not asked to take the rapid antigen test as well.

Australia sent COVID-19 supplies from Sydney to India last week. Photo: DFAT

Professor McLaws said it would have been far better for passengers who registered a very low viral load to be allowed to take the antigen test, to check if there was a false result, and to make sure the person was not just carrying tiny amounts of the disease in their system from an old infection.

“The stakes of having a positive test result while in India are so high. It means that they can’t come home … these low levels need to be validated with a second test,” she said.

“And particularly, a test that is a different type of test, a rapid antigen test, which picks up very low levels of viral load that would indicate whether somebody actually had an infection.”

Pathology Technology Australia chief executive Dean Whiting also said the number of positive results in the passenger cohort was “much higher” than in the broader Indian population.

He said it was also perplexing that so many people got a positive result given they had largely been self-isolating ahead of the flight to ensure they did not get sick.

“Given that I imagine most of these people are highly motivated to fly they would have been taking huge precautions in the first place, isolating themselves,” he told the ABC.

“So that would raise alarm bells straight away. Why has such a huge proportion in a small cohort of people tested positive?”

He said while PCR testing was “enormously reliable” when done in a good quality laboratory, there was always a risk of contamination.

“You can find circumstances where the tests are not used correctly, where you have contamination from one sample to the next, or where the environment for testing the samples isn’t standard,” he said.

“You could imagine contamination from one sample to the next. That would give you the low viral load kind of result that you’re talking about.”

In a statement, a Qantas spokesperson said it used an “accredited diagnostic agency” for its repatriation testing, but the airline was now “investigating if the diagnostic agency used another local laboratory for the pre-departure tests”.

“If there are concerns we will work together with DFAT to ensure the process is working as it should,” they said.

“The reason we went to India was to bring home as many Australians as possible. Together with the Department of Foreign Affairs and Trade (DFAT) all the protocols put in place were designed to minimise the risk of importing the virus and maximise the safety of everyone on board.”

The ABC has approached DFAT for comment but has not yet received a response.

-ABC