China began developing Covid-19 vaccines in mid-November 2019 before the official start of the outbreak - US Senate claims

A 300-page document, compiled by the US Senate, suggests Chinese researchers started work on a vaccine programme in mid-November of 2019.

The report also concludes that the pandemic most likely came from a lab leak and was the result of a 'research- related incident' in Wuhan. And it even suggests there may have been two unintentional spill-over events just weeks apart.

The document, which was released to US news website Axios, is the full version of a 35-page summary published in October by the Senate Health, Education, Labour and Pensions Committee.

It said: 'The Covid-19 pandemic was, more likely than not, the result of a research-related incident. 'New information, made publicly available and independently verifiable, could change this assessment. 'However, the hypothesis of a natural zoonotic origin no longer deserves the benefit of the doubt, or the presumption of accuracy.' One section of the report focuses on China's vaccine development.