, Dr Li who travelled to the US in late April, said she was one of the first people to begin researching the new virus, but that her efforts were stifled.
"The reason I came to the U.S. is because I deliver the message of the truth of COVID," she said.
"If I tell it in Hong Kong, the moment I start to tell it I will be disappeared and killed."
The claims come days after a new security law was passed in Hong Kong that critics say will allow Beijing to target its political opponents within the territory.
Dr Li said she her supervisor first asked her to conduct a "secret" investigation into a new "SARS-like" virus in Wuhan on December 31 of last year.
"The China government refused to get overseas experts, even including ones in Hong Kong, to do research in China," she said.
"So I turned to my friends to get more information."
She said she then spoke to a number of contacts, including one who worked at China's Center for Disease Control and Prevention.
She said the friend told her of an unknown virus that had emerged in Wuhan and that "family cluster cases", an indicator of human-to-human transmission, had been observed.
She was also told that the number of cases was thought to be rising exponentially.
She claims that, when she took her findings to her superior, she was told to "keep silent and be careful".
"He warned me..., 'Don't touch the red line'," Dr Li said, referring to the unspoken limits placed by Beijing on such investigations.
"'We will get in trouble and we'll be disappeared'."
The last week has seen Beijing impose draconian new laws in Hong Kong, previously guaranteed autonomy under an arrangement known as "one country, two systems".
The law is vaguely worded, but targets offences such as secession, subversion, terrorism, and collusion with foreign forces.
Critics say the law will erode the freedom of the press, the independence of the judiciary, and the right to peaceful protest within the territory.
The claims come after Beijing imposed draconian new laws within Hong Kong Credit: Getty - Contributor