Editor's Note: This article originally appeared on Business Insider.

A Chinese government spokesman said Thursday that “it might be U.S. Army who brought the epidemic to Wuhan,” pushing one of several popular coronavirus conspiracy theories in China.

Zhao Lijian, a Ministry of Foreign Affairs spokesman, called attention to the admission Wednesday by Robert Redfield, the director of the US Centers for Disease Control and Prevention, that some Americans who were said to have died from influenza may have actually died from the coronavirus (COVID-19).

“When did patient zero begin in U.S.? How many people are infected?” he asked. “What are the names of the hospitals? It might be U.S. Army who brought the epidemic to Wuhan. Be transparent! Make public your data! U.S. owe us an explanation!”

In a short thread on Twitter, a social media platform inaccessible in China, Zhao demanded to know how many of the 34 million influenza infections and 20,000 associated deaths during this latest flu season were related to COVID-19.

The coronavirus, now a pandemic, first appeared in the central Chinese city of Wuhan, capital of hard-hit Hubei province and the epicenter of a serious outbreak that has claimed the lives of thousands, the majority in China.

As China has faced criticism, Chinese authorities have been pushing back, suggesting that the virus may have originated somewhere other than China. Dr. Zhong Nanshan, a leading Chinese epidemiologist, said in late February that “though the COVID-19 was first discovered in China, it does not mean that it originated from China.”

Zhao, in his role as a government spokesman, stressed the same point in a recent press briefing.

“No conclusion has been reached yet on the origin of the virus,” he told reporters, adding that “what we are experiencing now is a global phenomenon with its source still undetermined.”

One popular conspiracy theory that has emerged about the coronavirus is that American athletes participating in the Military World Games, an event held in Wuhan last year, may have brought the virus, either intentionally or accidentally, into China. There is no evidence to support this accusation.

The Trump administration has laid the blame firmly at China's feet though. “Unfortunately, rather than using best practices, this outbreak in Wuhan was covered up,” White House national security adviser Robert O'Brien told reporters Wednesday.

“It probably cost the world community two months to respond,” he added.

Another Chinese foreign ministry spokesman, Geng Shuang, called O'Brien's efforts to denigrate China's efforts to fight the virus “immoral and irresponsible.”

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