China refused to give raw data on early Covid-19 cases to a World Health Organisation (WHO)-led team probing the origins of the pandemic, one of the team's investigators said, potentially complicating efforts to understand how the outbreak began.

The team had requested raw patient data on 174 cases that China had identified from the early phase of the outbreak in the city of Wuhan in December 2019, as well as other cases, but were only provided with a summary, said Dominic Dwyer, an Australian infectious diseases expert who is a member of the team...