The World Health Organisation has previously said that the first reported instance of the novel coronavirus outside China was in Thailand in January.
But on Monday a French hospital -- Groupe Hospitalier Paris Seine -- said it had evidence that a patient treated in December was carrying the virus. The evidence was published in the International Journal of Antimicrobial Agents on Sunday.
Asked about the hospital’s report, the WHO told CNN on Tuesday: "We are aware of a paper describing a potential case of Covid-19 in France in December. The paper reports on samples collected on 27 December that were positive for Covid-19, which is earlier than the first reported cases in France in January."
"This finding helps to better understand potential virus circulation of Covid-19. The finding is not surprising given the earliest cases of Covid-19 had symptom onset in early December. It is possible that some infected people traveled from Wuhan to other countries at that time."
The WHO added that it was possible more early cases of the virus would be found as countries went back and re-tested samples from patients who were sick in December, January or even earlier.
Dr Yves Cohen, a Paris doctor, did a re-test on the original patient from December.
"We picked up the sample which had been frozen, and we ran it through the SCR test, we did it twice to confirm it was positive," he told French television.
"Then we looked at the medical file again, we took another look at the scan of the thorax, and he did have Covid zones, Covid specifications. And the biological results were very inflammatory, like you find with Covid-19 patients."