The coronavirus pandemic may have started as early as October, Britain’s Telegraph reported Friday, citing a new joint study by University College London and the University of Reunion Island.

Doubts about the outbreak’s previously reported starting point emerged after a French athlete, who fell ill after competing in the Military World Games held in Wuhan in October, said she had been told by doctors she’d likely contracted Covid-19.

The study’s findings are based on analysis of more than 7,000 genome sequence assemblies collected worldwide since January and will be published in a forthcoming edition of scientific journal Infection Genetics and Evolution, the newspaper said.

Separately, it has been suggested that one of the first patients to emerge in China was a 55-year-old resident of Hubei province on November 17, according to Chinese government information, seen previously by the South China Morning Post. “Patient zero” has not yet been confirmed, the newspaper reported.