The World Health Organization (WHO) has said its newly established task force could be the “last chance” to find the truth over the origins of the coronavirus pandemic.

Nearly two years since the coronavirus was first detected in the Chinese city of Wuhan, its origins remain unclear and experts continue to question whether the virus jumped from animals to humans or if it could have leaked from a laboratory.

In February, a joint WHO-China mission concluded that the theory of a leak from a laboratory in Wuhan was “very unlikely” and that it did not warrant further investigation.

However, the WHO’s director general voiced his frustration over the level of access China had granted to the international mission to China.

Tedros Adhanom Ghebreyesus said the mission’s final report did not conduct an “extensive enough” assessment over the possibility the virus was introduced to humans through a laboratory incident.

The WHO on Wednesday announced the names of 26 nominees to join the newly established Scientific Advisory Group for the Origins of Novel Pathogensa (SAGO).

The proposed team of scientists includes six people who visited China as part of the previous WHO-China mission.

The members’ appointment will be formalised in two weeks after a period of public consultation, the WHO said.

The WHO was seeking to “take a step back, create an environment where we can again look at the scientific issues”, said Michael Ryan, the WHO’s emergencies director. “This is our best chance, and it may be our last chance to understand the origins of this virus,” he added.

On Wednesday, WHO epidemiologist Maria Van Kerkhove, Ryan and Tedros published an editorial in the journal Science stressing the fact that “laboratory hypotheses must be examined carefully … A lab accident cannot be ruled out until there is sufficient evidence to do so and those results are openly shared”.

China has repeatedly denied the lab leak possibility and said no more visits were needed.

The country’s ambassador to the United Nations in Geneva, Chen Xu, told a separate news conference the conclusions of the WHO-China joint study were “quite clear”.

“It is time to send teams to other places,” he said adding that international teams had been sent to China twice already

The new team was not solely set up to find where the virus came from, but also to establish a framework for the future.

“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,” said Tedros.