This story was published on July 14, 2019.

A researcher with ties to China was recently escorted out of the National Microbiology Lab (NML) in Winnipeg amid an RCMP investigation into what's being described as a possible "policy breach."

Dr. Xiangguo Qiu, her husband Keding Cheng and an unknown number of her students from China were removed from Canada's only level-4 lab on July 5, CBC News has learned.

A Level 4 virology facility is a lab equipped to work with the most serious and deadly human and animal diseases. That makes the Arlington Street lab one of only a handful in North America capable of handling pathogens requiring the highest level of containment, such as Ebola.

Security access for the couple and the Chinese students was revoked, according to sources who work at the lab and do not want to be identified because they fear consequences for speaking out.

Sources say this comes several months after IT specialists for the NML entered Qiu's office after-hours and replaced her computer. Her regular trips to China also started being denied.

At meetings on July 8, NML staff were told the researchers are on leave for an unknown period of time. They were told not to communicate with them.

Qiu is a prominent virologist who helped develop ZMapp , a treatment for the deadly Ebola virus which killed more than 11,000 people in West Africa between 2014-2016.

She worked with Gary Kobinger , who is now a professor in the Department of Microbiology and Infectious Diseases and director of the Research Centre on Infectious Diseases at Laval University in Quebec.

Affiliated with Chinese university

Qiu is a medical doctor from Tianjin, China, who came to Canada for graduate studies in 1996. She is still affiliated with the university there and has brought in many students over the years to help with her work.

Currently head of the Vaccine Development and Antiviral Therapies section in the Special Pathogens Program at the lab, Qiu's primary field is immunology. Her research focuses on vaccine development, post-exposure therapeutics and rapid diagnostics of viruses like Ebola.

She is also an adjunct professor in the Department of Medical Microbiology at the University of Manitoba.

Cheng also works at the lab as a biologist. He has published research papers on HIV infections, Severe Acute Respiratory Syndrome (SARS), E. coli infections and Creutzfeldt-Jakob Syndrome.

Dr. Xiangguo Qiu, research scientist, second from right, and Dr. Gary Kobinger, former chief of special pathogens, right, are two of the National Microbiology Lab scientists who created the Ebola treatment, ZMapp. Also pictured, at left, Dr. Kent Brantly and Dr. Linda Mobula, assistant professor at Johns Hopkins School of Medicine and the physician who administered ZMapp to Dr. Brantly in Liberia. (Submitted by Health Canada)

The RCMP received a referral from the Public Health Agency of Canada (PHAC) on May 24.

"Based on information received to date, the RCMP has assessed that there is no threat to public safety at this time," Robert Cyrenne said in an email to CBC News on Thursday.

PHAC is describing it as a policy breach and "administrative matter" and says the department is taking steps to "resolve it expeditiously," Eric Morrissette, the health agency's chief of media relations, said from Ottawa.

No one is under arrest or confined to their home, he added.

When asked for a response to the latest details, Morrissette said there would be no further comment "for privacy reasons."

A spokesperson for Health Minister Ginette Petitpas Taylor said she is aware of an "administrative investigation" at the lab but has no comment.

Xiangguo Qiu works in level-4 containment at the National Microbiology Laboratory in Winnipeg. (CBC News)

"We can assure Canadians that there is absolutely no risk to the Canadian public and that the work of the NML continues in support of the health and safety of all Canadians," communications director Mathieu Filion said in an email Saturday.

Matthew Gilmour, scientific director general of the NML, did not respond to a request for comment.

A spokesperson for the Canada Border Services Agency said the department will not confirm or deny whether anyone has been arrested or is under investigation. That information would only be public if charges are laid, Judith Gadbois-St-Cyr said in an email Thursday.

No one from the Chinese Embassy could be reached for comment.

'Microbiology can ... involve national security'

While there are few details available, experts say this could be a case of intellectual property theft or technology leakage to China.

"The National Microbiology Laboratory would have some pretty sensitive biological research material that ... could be shared either with or without authorization with foreign countries," said Gordon Houlden, director of the University of Alberta's China Institute.

"All of this is unproven, but even microbiology, sometimes especially microbiology, can have issues that involve national security."

It's something the Canadian Security Intelligence Service has already warned about, said Leah West, who teaches national security law at Carleton's Norman Paterson School of International Affairs.

"Canada is facing threats from foreign governments seeking to steal intellectual property and that could include state-funded research," she said.

"The two big things I want to see is whether or not these individuals are charged with crimes by the RCMP ...that will give us a lot of information about what is really at stake here."

West is also interested in seeing how this plays out politically between Canada and the Chinese government.

The National Microbiology Lab in Winnipeg is one of only a handful in North America capable of handling dangerous pathogens such as Ebola. (Trevor Brine/CBC)

Relations between the two countries have been strained since the detention of Huawei executive Meng Wanzhou on a U.S. arrest warrant.

"China and Canada's relationship right now stems from China using espionage to advance its strategic interests, be that its security interests or its economic interests," West said. "How Canada deals with that going forward, especially given that we have two Canadians who remain in Chinese custody, will be very interesting to watch."

This isn't the first time police have investigated an incident at the lab.

In 2009, a former researcher at the lab was convicted of trying to smuggle genetic material from the Ebola virus across the Manitoba-North Dakota border.

The FBI is also investigating cases involving Chinese researchers in the United States.