After the city of Beijing announced its first reported case of the Omicron variant, Chinese officials alleged that the virus may have travelled to the city through a piece of mail from Canada—a claim experts say doesn't add up.

Dr. Supriya Sharma, chief medical adviser at Health Canada, calls the allegation “highly improbable.â€

“You would have to have virus on an object, it would have to survive through all of that transport and all of those circumstances,†Dr. Sharma told Â鶹´«Ã½ Channel’s Power Play. “It would be highly unlikely that that could ever transmit COVID-19.â€

“I think we know where the science is in terms of the main mode of transmission,†Dr. Howard Njoo, deputy chief public health officer at the Public Health Agency of Canada, said on Power Play.

“Certainly, the experience in Canada, and I think throughout the world, has shown that the main mode of transmission really is through the air as opposed to a transfer from inanimate surfaces.â€

In a Monday release, the (CDC) said that the city reported one case of the COVID-19 variant on Saturday in a 26-year-old woman. After conducting contact tracing, officials said the woman did not travel outside the capital and had not come in contact with anyone else with the virus.

However, the Beijing CDC says it examined the woman's mail, which included a letter sent on Jan. 7 from Canada, arriving in Beijing three days later via the United States and Hong Kong.

Officials allege that piece of mail had traces of the Omicron variant of the SARS-CoV-2 virus. This includes samples taken from the paper inside the envelope, even though the woman said she had only touched the outer surface of the package.

"The possibility of contracting the virus through foreign items cannot be ruled out," the Beijing CDC said in a translated news release.

"This doesn’t sound credible at all," Dr. Colin Furness, an expert in infectious disease epidemiology from the University of Toronto, told CTVNews.ca in an email, noting that surface transmission of COVID-19 through international mail is highly improbable, as it’s unlikely the virus would survive in transit.

"COVID’s ability to survive on paper depends partly on the roughness of the paper, but it’s unlikely to persist in an active state for more than a day or two,†Furness said. “High friction with other documents in a mailbag makes survival of even a day seem unlikely.â€

University of Saskatchewan epidemiologist Dr. Nazeem Muhajarine also calls the claims "bewildering."

"I would ask whether the 'officials' who claimed this have ruled out all other more plausible exposures to Omicron. Are these supposed viral particles isolated and tested viable? Is there any independent verification?" Muhajarine said in an email to CTVNews.ca.

"For this claim to carry any credibility, so many exceptional things have to line up."

The Beijing CDC is encouraging residents to wear gloves while handling packages, disinfect packaging with alcohol and avoid buying goods from overseas if possible.

However, Muhajarine says that reports of transmission of COVID-19 through surfaces are "exceedingly rare."

"We now know that this virus transmits most readily through the air via aerosolized means. Even then, it is likely that Omicron doesn’t maintain its viability to infect days after it is released into the air," he said.

When asked about the claims from Chinese officials, Canadian Health Minister Jean-Yves Duclos said the allegations are "certainly not in accordance with what we have done both internationally and domestically."

"I would say that the experts can tell us what to think," he told reporters in French on Monday. "I obviously have my own opinion. But for an opinion to be useful and credible, we need more information and I think the experts should speak."

Conservative Leader Erin O’Toole called the reports “comical.â€

“Obviously we’re very concerned with variants within the pandemic, variants that have come from outside of Canada but that we have to deal with here. Stories like this remind us that from the beginning of the pandemic, some of the news and reporting out of China could not be trusted,†he said at a Monday press conference.

The single reported case in Beijing has been identified at the worst possible time for the city, as it prepares to welcome thousands of athletes for the Olympics -- including from countries where Omicron is raging.

Furness also notes that geopolitics may be a part of why Chinese authorities are pointing the finger at Canada.

"Sino-Canadian relations are in poor shape, and China may be very keen to counter accusations that it infected the world, with these sorts of narratives," he said.

The first known case of COVID-19 was identified in Wuhan, China in Dec. 2019.

With files from The Associated Press.