A joint World Health Organization (WHO)-China study on the origins of Covid-19 says that the virus was probably transmitted from bats to humans through another animal, and that a lab leak was "extremely unlikely" as a cause, a summary seen by Reuters said on Monday.

The WHO did not immediately reply to a query seeking comment, but said the full report by the independent experts would be published on Tuesday at 1400 GMT (10pm Malaysia time) after member states have been briefed...