SHANGHAI – The virus that causes COVID-19 could have started spreading in China as early as October 2019, two months before the first case was identified in the central city of Wuhan, a new study showed on June 25.
Coronavirus
Reuters: First COVID-19 case could have emerged in China in October 2019 – study

This photo taken on Feb. 6, 2020, shows a discarded face mask, used as a preventative measure following a coronavirus outbreak which began in the Chinese city of Wuhan, in vegetation in Liu Pok village in Hong Kong, with the skyline of the Chinese city of Shenzhen (back) in the distance.