The World Health Organization's team of international experts tracking the origins of COVID-19 said its investigation was going "really well, excellent," according to EcoHealth Alliance president Peter Daszak, a member.
An organization official in Geneva said the organization had held "very good discussions" with China authorities.
Meanwhile, the team searched an animal health center in China's Wuhan on Tuesday.
It has already visited hospitals, a regional disease control center and the city's Huanan seafood market, where the first cluster of infections was believed to have originated in late 2019.
The team said the animal health center, which fights epidemic diseases in animals, might provide information on how a coronavirus endemic in bats in southwest China might have crossed into humans.
On Monday, the organization's top emergency official, Mike Ryan, said the investigation might not find all the answers to the origins of COVID-19, describing the mission as a "detective story" that continued to raise new questions. He said the investigation "deserves the support of the international community and it deserves to be able to finish its work," Ryan said.
The team's visits are coordinated by China authorities. The organization said while expectations were running high for the origins of the virus to be unraveled, the 13-member group's activities would be limited. Members aren't permitted contact with anyone from the community to prevent health risks.
On Monday, the team visited the Hubei Provincial Center for Disease Control and Prevention. News reports said the team spent more than four and a half hours there. They didn't elaborate.
It also searched the Huanan wet market - which has been sealed off to the public. It was where the virus was first detected. The World Health Organization members were accompanied by heavy security.
This past weekend was a packed one for the COVID hunters with two hospitals where the first confirmed cases were treated on the itinerary.
The Wuhan Jinyintan Hospital was the first to admit infected patients and is thought to have critical epidemiological links to the virus.
Daszak said in a tweet after the Jinyintan Hospital visit that the visit was an "important opportunity to talk directly" with medical professionals who were part of the first response team.
Meanwhile, in related news China will suspend religious gatherings in many places during the Lunar New Year holidays as part of efforts to curb the virus wave.
Several towns and cities including Chengdu and Beijing have suspended religious gatherings that attract crowds.
Other cities and provinces have yet to announce COVID-19 restrictions during the holidays but it is expected strict curbs will be imposed.
There is no news about the restriction affecting the World Health Organization's movements in Wuhan.
