The World Health Organization (WHO) says a new taskforce may be the last chance to find the origins of Covid-19.
More than a year-and-a-half since the virus was detected in the Chinese city of Wuhan, the question of how it first emerged remains unclear.
The team will consider if the virus jumped from animals to humans in Wuhan markets or leaked in a lab accident.
China has strongly refuted the second theory.
In February, a WHO team tasked with investigating Covid's origins flew to China and concluded that the virus had probably come from bats but that more work was needed.