The Chinese embassy in Paris has tracked down a woman from Wuhan who said she took tablets to pass airport health checks.
The woman boasted on social media that she had been suffering from a fever, but managed to reduce her symptoms with medicine.
She later posted pictures showing herself dining at what she claimed was a Michelin-starred restaurant in Lyon.
The embassy has now confirmed that her symptoms are under control.
The woman left Wuhan – where the new coronavrius emerged late last year – before flights were suspended, but when thermal scanning was in place.
Since yesterday, public transport has been shut down, with residents told not to leave the city.
At least 25 people with the virus have died. It was first reported to the World Health Organization 31 December.
The virus has spread to countries as far as South Korea, Japan and the US.
The woman detailed her journey to Lyon on social media site WeChat.
“Finally I can have a good meal, I feel like I’ve been starving for two days. When you are in a gourmet city of course you have to eat Michelin [food],” she wrote.
“Just before I left, I had a low fever and cough. I was scared to death and rushed to eat [fever-reducing] medicine. I kept on checking my temperature. Luckily I managed to get it down and my exit was smooth.”
She also posted pictures of the meal she enjoyed. It is not clear exactly when she arrived.
Her post quickly went viral and she was widely criticised by other social media users.
The Chinese embassy in Paris said it had received calls and emails about the woman. It said she had taken antipyretics, and that it attached “great importance” to the case.
The embassy said it contacted her on Wednesday evening and asked her to refer herself to medical services.
On Thursday, in a new statement, the embassy said the woman’s temperature was under control, and that she had no more fever or cough symptoms.
It added that she did not require “further examinations” at this point.
China has effectively quarantined nearly 20 million people in Hubei province. Other major cities in China like Beijing and Shanghai are also affected.
Authorities have cancelled all large-scale celebrations in Beijing. Temple fairs are banned, film releases postponed and the Forbidden City will be closed to the public.
All this comes as millions of Chinese people are travelling across the country for Lunar New Year.
Currently known as 2019-nCoV, the virus is understood to be a new strain of coronavirus not previously identified in humans.