A top Chinese health official said the government doesn't accept World Health Organization plans for a follow-up investigation into COVID-19's origins and called theories of a laboratory leak a "rumor," per AP.

Why it matters: National Health Commission Vice Minister Zeng Yixin's comments come days after WHO Director-General Tedros Adhanom Ghebreyesus said it was "too early" to rule out a potential connection between the pandemic and and a leak from a lab.

What they're saying: Zeng said he was "surprised" by a WHO proposal to revisit Wuhan, the first epicenter of the coronavirus, which a group of researchers from the health body visited in January — labeling the plan "not scientific," according to Al Jazeera.

The big picture: The debate over the origins of the coronavirus has gained traction in recent months following previously undisclosed U.S. intelligence that three researchers at the Wuhan Institute of Virology fell ill enough to be hospitalized in November 2019, as first reported by the Wall Street Journal in May.

Go deeper: Why we need to know COVID's origins

Editor's note: This a breaking news story. Please check back for updates.