The World Health Organization has introduced a team of experts it hopes will resurrect the delayed investigation into the origins of COVID-19, with one top official claiming it may be the final opportunity.

The group of 26 specialists will be tasked with developing a new global framework for research into the origins of emerging infections with epidemic and pandemic potential - including Sars-CoV-2, the virus that causes COVID-19.

Its 26 members were chosen from a pool of over 700 applications and represent a variety of scientific disciplines.

According to Michael Ryan, the WHO's director of emergencies, it may be the "last chance to understand the origins of this virus" in a collaborative manner.

Earlier this year, the WHO announced the formation of a Scientific Advisory Group for the Origins of Novel Pathogens (SAGO).

"The emergence of new viruses with the potential to spark epidemics and pandemics is a fact of nature, and while SARS-CoV-2 is the latest such virus, it will not be the last," WHO chief Tedros Adhanom Ghebreyesus said.

"Understanding where new pathogens come from is essential for preventing future outbreaks."

It's been more than a year and a half since the virus was discovered in the Chinese city of Wuhan, and no one knows how it got there. The researchers will look into whether the virus spread from animals to humans in Wuhan markets or if it was accidentally released in a lab.

The second theory has been completely discredited by China.

A WHO team entrusted with examining COVID-19's origins traveled to China in February and found that the virus was most likely transmitted by bats, but that more research was needed.

The study was chastised for a lack of transparency and access, as well as for not thoroughly examining the lab-leak theory.

Earlier Wednesday, China's ambassador to the UN in Geneva, Chen Xu, told the UN correspondents' association that SAGO's work should not be "politicized."

"If we are going to send teams to any other places, I believe it's not to China because we have received international teams twice already," he said.

"It's time to send teams to other places."

In August, China rejected the WHO's calls for a renewed probe on the ground into the origins of COVID-19.