A sample taken from a patient in December 2019 in the suburbs of Paris tested positive for COVID-19, making him the earliest-known coronavirus patient outside of China.
"It all started around December 20, when I started to have a dry cough, for about a week I had a dry cough every day. Then came the fever which, for three days, went over 40 degrees, said Amirouche Hammar, the patient from Bobigny, who thought he suffered from a lung infection, in footage from Thursday.
"Then I started to have chest pain, a strong pain in my chest and the night before I went to the hospital, I started coughing blood."
Hammar said about two weeks ago, his doctor called him with the news that what he suffered from was COVID-19.
The new discovery upends the previous understanding of the epidemic's timeline, as authorities would not acknowledge evidence of human-to-human transmission before mid-January.
The previously known first case outside China was a woman who travelled from Wuhan, the epicentre of the disease, to Thailand on January 13, while the first known cases in Europe before Hammar were Chinese nationals who arrived in Bordeaux on January 24.
Unlike these cases, Hammar had not travelled or come into contact with other known patients.
"Maybe I bumped into people, maybe I've infected them but what I'm really wondering is how I have been infected in December. The epidemic just started in China and five days after it was in France," he said.
Researchers believe that his wife Fatiha Hammar might have been the first carrier of the disease after getting it at a fish market next to a sushi counter where she works, near Charles de Gaulle airport in Paris.
The coronavirus, which was not reported to the World Health Organization until the end of December, was discovered Wuhan earlier that month. Early theories link the emergence of the virus to a Wuhan market selling meat from wild animals.