BEIJING (NewsNation Now) — The World Health Organization's report on the origins of the coronavirus following a mission to Wuhan, China, will be released on Tuesday, but further study is required.

A draft of the report obtained by The Associated Press on Monday said it is most probable that the transmission of the virus from bats to humans through another animal is the most likely scenario and that a lab leak is “extremely unlikely.”

The scientists proposed further research in every area except the lab leak hypothesis, the AP reported, citing a draft copy of the report, which it said left many questions unanswered.

The AP received what appeared to be a near-final version from a Geneva-based diplomat. It wasn’t clear whether the report might still be changed prior to its released, the AP said.

Peter Ben Embarek, the WHO expert who led the mission to Wuhan, China, said Friday that the report had been finalized and was being fact-checked and translated.

“I expect that in the next few days, that whole process will be completed and we will be able to release it publicly,” he said.

More than 20 heads of government and global agencies called in a commentary published Tuesday for an international treaty for pandemic preparedness that they say will protect future generations.