Dr. Lucey’s fifth question addresses a detailed report in The South China Morning Post, published in Hong Kong, that identified an early human coronavirus case on Nov. 17 in Hubei province. The province is the size of Washington State, and Wuhan is its capital. In March, Dr. Lucey wrote a blog post about the report, which described the virus’s rapid spread in Hubei, based on information that the report said came from the government. Now, Dr. Lucey is urging the investigators from the World Health Organization to determine where each of these early Hubei cases were reported, if indeed they occurred, and whether any other “documented or suspected” human infections may have occurred even earlier.

The sixth and seventh questions go to whether the deadly pathogen leapt to humans from a laboratory. Although some intelligence analysts and scientists have entertained that scenario, no direct evidence has come to light suggesting that the coronavirus escaped from one of Wuhan’s labs.

Even so, given the wet market’s downgrading in the investigation, “It is important to address questions about any potential laboratory source of the virus, whether in Wuhan or elsewhere,” Dr. Lucey wrote in his blog post.

To that end, he urges the W.H.O. investigators to look for any signs of “gain of function” research — the deliberate enhancement of pathogens to make them more dangerous. The technique is highly contentious. Critics question its merits and warn that it could lead to catastrophic lab leaks. Proponents see it as a legitimate way to learn how viruses and other infectious organisms might evolve to infect and kill people, and thus help in devising new protections and precautions.

Debate over its wisdom erupted in 2011 after researchers announced success in making the highly lethal H5N1 strain of avian flu easily transmissible through the air between ferrets, at least in the laboratory.

In his blog, Dr. Lucey asks “what, if any,” gain-of-function studies were done on coronaviruses in Wuhan, elsewhere in China, or in collaboration with foreign laboratories.

“If done well scientifically, then this investigation should allay persistent concerns about the origin of this virus,” he wrote. “It could also help set an improved standard for investigating and stopping the awful viruses, and other pathogens, in the decades ahead.”