An employee of a biotech company in the United States, who is under criminal investigation by Beijing police for concealing her novel coronavirus symptoms during a flight to China, has been dismissed by her company.

Biogen, a drugmaker based in Cambridge, Massachusetts, said in a statement on Sina Weibo on Friday that the 37-year-old, surnamed Li, was an employee of the company, but she made the decision to travel to China without informing the company and ignored the guidance of health experts.

Her behavior is against the company's values, and she is no longer an employee of Biogen, it said.

Li, a Chinese citizen living in Massachusetts, flew to Beijing on March 12 with her husband and son to seek treatment after one of her US colleagues tested positive for the coronavirus.

She had a fever but lied to the crew about her health status and took a drug to reduce her fever before boarding. She also initially hid the fact that she was traveling with her husband and son on the same flight.

She tested positive for the coronavirus after arriving in Beijing and is now being treated, and her husband was later confirmed to be infected with the virus.

According to a government guideline issued on Monday, overseas passengers are subject to temperature screening, health declaration and epidemiological investigation across checkpoints. People who refuse to receive isolated observation or fail to truthfully fill out their health declaration forms at border checkpoints could face criminal penalties.

In Li's case, police have launched an investigation against her for obstructing infectious disease prevention and putting fellow travelers at risk of infection.

Earlier this week an employee of Bayer, a German chemical and pharmaceutical company, was fired and asked to leave China for breaking the coronavirus quarantine.

After returning to her residence in Beijing last week from abroad, the 47-year-old Chinese Australian woman surnamed Liang was seen jogging in the residential quarter without a mask when she was supposed to be quarantined at home for 14 days.

The video of her refusing to follow quarantine went viral online, and Bayer China on Tuesday decided to fire her.

Liang was also asked to leave China within a specified period of time by Beijing police and her work-related residence permit was revoked.