It's bad enough that China has frozen exports of medical equipment to the US during the pandemic. Now a new report sheds light on some COVID-19 test kits from the country that were sent "contaminated."

The South China Morning Post (SCMP) said the University of Washington School of Medicine (UW Medicine) "went to extraordinary lengths to airlift tens of thousands of Covid-19 testing kits" during the start of the US outbreak to only discover last week that some of the tests are tainted.

"I've just recommended everyone who has these things pause and not use them at all," said Geoff Baird, the interim chair of the UW Department of Laboratory Medicine, who led the group to secure the tests. "I can't say I'm not disappointed."

Baird told SCMP that a colleague informed him on April 16 that some of the "liquid in vials he had sent appeared to have changed in color." In shock, he said he stormed out of his office down to the UW Medicine storage facility where the test kits were being held and started to "tear through boxes."

COVID-19 testing vial. (Photo: AFP)

He said many of the vials looked "fine," but a "small percentage of them had turned to an orange or yellow color, rather than hot pink," which indicated bacterial growth and, ultimately, contamination.

Baird also had scientists add novel coronavirus to the contaminated vials and compared to uncontaminated liquid.

The conclusions, he said: "There's absolutely no difference."

After that, Baird immediately suspended future orders with the Chinese manufacturer.

Anita Nadelson, the Seattle businesswoman who helped the university secure the tests, said the Chinese firm would refund their money.

"They're working diligently to identify and cure the issue," Nadelson said. "We vetted these as best we could. It's an unexpected turn on both sides."

Baird said the contamination is concentrated in the specimen-preserving liquid, which makes no contact with patients, adding that "we don't expect there's any real mechanism of harm to patients."

A scientist runs a clinical test at UW Virology's lab. (Photo by Karen Ducey/Getty Images)

He said S. maltophilia was the bacterium found in the contaminated vials:

"It lives on surfaces and it lives on factory things and tubing," he said. "I would think it's in your home, my home, it's on everything."

Baird said the university gave 20,000 test kits to Public Health–Seattle & King County and another 15,000 to the state.

"I don't know how many they've distributed yet," he said.

On Sunday, the state recalled 12,000 kits it handed out to counties.

"We are working with our partners to have them discard the product and will work to replace them as quickly as we can," said John Wiesman, the state secretary of health, in a statement.

"About 5,000 of the 20,000 they gave us had been distributed by us, and approximately 300 had been used," said James Apa, a Public Health–Seattle & King County spokesman, adding that "the problem with the kit itself shouldn't present any health risk to patients."

Baird said while the contaminated test kits are a setback – there appears to be a national shortage of kits.

"We should be doing more, but we've not seen our volume go up," Baird said of testing at the UW Medicine facility. "There's a cap on the amount of testing that can be done globally, and certainly nationally, there aren't enough kits for swabs and VTM (viral transport media) for testing."

Defective tests from China were not limited to the US. We noted earlier this month Spain received 640,000 tests that were later considered useless.

While China attempts to restore its image as a global leader and focus on distributing humanitarian relief to countries in need, the latest snafu of contaminated or defective COVID-19 testing kits is a public relations disaster.