A team of international and Chinese scientists is poised to report on its joint search for the origins of the coronavirus that sparked a pandemic after it was first detected in China over a year ago.

Four theories are being considered, and one is the clear frontrunner: That the virus first emerged in humans by way of a bat and then an intermediate host.

Last month, a team member summarized the other three suspected origins, in order of likelihood: that the virus jumped to humans directly from a bat; via contaminated frozen food products and a potential leak from a laboratory like the Wuhan Institute of Virology.

The lengthy report is being published after months of wrangling, notably between the U.S. and Chinese governments, over how the outbreak emerged, causing politics to overshadow a scientific search.

It wasn’t immediately clear when the report will be released after its publication was delayed earlier this month.