RT has pointed out that claims of a coronavirus lab leak were once dismissed in the U.S. media as implausible and dangerous, but it is now a heated theory discussed by many.

The Russian news service noted in an article published on July 23 the theory that the virus might have leaked from a lab in Wuhan was "taken up by the administration under former U.S. President Donald Trump in the first months of the health crisis."

"At the time, U.S. media dismissed the idea as implausible and even dangerous misinformation. However, the theory has become mainstream in recent months after Washington began to question the completeness of the WHO's preliminary surveys," according to the article.

A World Health Organization (WHO) team consisting of international experts arrived in Wuhan, China on January 14. After their field trip and study with Chinese experts, they formed a joint report which stated a lab leak was "extremely unlikely."

After the report was published, U.S. President Joe Biden instructed the U.S. intelligence agencies to conduct their own investigation into the origin of the health crisis.

"The experts, selected by the WHO, were authoritative in their respective fields and were rich in research experience. We should respect their conclusions," Zeng Yixin, deputy head of China's National Health Commission, said at a recent press briefing.

China also opposes the WHO's second phase plan on origin tracing, which concentrates on the "lab leak" theory.

Zhao Lijian, spokesperson for the Chinese Foreign Ministry, said the plan was "put forward unilaterally by the WHO Secretariat without getting the approval of all member states."

He said 60 countries had written to the WHO director general saying that they "welcome the joint WHO-China study report and reject politicizing origin studies."

Zhao said China has submitted a research proposal for the next phase based on the previous jointly studies and will continue to act on "relevant work recommendations in the joint WHO-China study report and actively conduct further follow-up research." 

Read more: China says WHO's plan to focus on lab leak lacks common sense