In a non-peer-reviewed and unpublished seven paragraph paper on Researchgate in April 2020 (since withdrawn, but copied to many other servers elsewhere), Huazhong University DNA researcher Botao Xiao ( older description ) ( Google Scholar ) and Lei Xiao claim that Covid-19 escaped from bat research into the Wuhan population from the China Center for Disease Control and Prevention provincial office in Wuhan, Hubei. AFAIK, the Class 2 lab in Wuhan merely investigates unusual infectious disease at hospitals in Hubei province and performs no wildlife research.
Animal and virus research occurs at the Wuhan Institute of Virology.
Xiao's claims that such research occurs at Wuhan CDC, and that bats were not sold for food at the Wuhan seafood market, are not supported by any citations. A quick google search finds many references to bat dishes. We know that selling bats for food is now illegal in China, yet Yewei ("wild taste") was popular, and legal, in 2019. We also know that other carnivorous mammals (like mink and cats) can be infected by SARS-COVID-19, and one of those may have eaten a dead bat, then ended up as meat in the Wuhan seafood market. There are indeed many mysteries, but we know the virus is 97% identical to a bat virus, and that bats have very high virus loads.
While Xiao claims that the virus somehow travelled from the Wuhan CDC office to infect an individual at the wet market 280 meters away, this is not consistent with typical social distance recommendations of 2 meters for an active human carrier. There is no way that a virus can travel that distance without an infected human or animal host carrying it.
This withdrawn preprint still circulates among the fringe right wing, and was quoted by non-science-writer Nicholson Baker in an article in New York Magazine (not to be confused with the more reputable New York Times magazine or the New Yorker magazine).
Published 2021/01/04, The Lab Leak Hypothesis makes strange statements like "no public investigation has taken place. We still know very little about the origins of this disease." That is true of Baker and New York Magazine, and may have been true at the end of 2019, but not now, and not of the thousands of researchers and peer-reviewed authors who evaluated the genetic sequence, tied it to bats, and track the thousands of variants by their genetic sequence.
Some claim that SARS-COVID-19 was genetically engineered as a biowarfare agent. This was easily dismissed by professional virologists; they know (but thankfully do not publish) how a far more lethal and infectious virus could be created and spread. The pathologically counter-productive handling of the pandemic in the US and Europe demonstrates how vulnerable the west is to viral biowarfare. We should not focus on the past, but how very poorly prepared we are for a future, directed, optimized attack, perhaps designed to exploit some peculiarity of European genetics (African-Americans are on average 24% genetically European, and also at risk). Prepare for COVID-21 or -22, don't antagonize those who might create it.
Read some of the peer-reviewed papers, in Science, Nature, Cell, and many other specialty journals. Learn what the real researchers know, and more importantly, what they still don't know but strive to find out. Science is a global, collaborative activity, always updating and changing as new experiments are made and new facts emerge. Dr. Xiao is allowed to have an opinion, and is allowed to call himself a scientist, but he is not allowed to designate his opinion as a scientific fact without the concurrence of the subject experts - which he is not. New York Magazine is not a scientific magazine, and is not peer reviewed. Nor are the crackpots who keep reposting Xiao's withdrawn brief paper of April 2020.
It would be interesting to get the story of this paper from Botao Xiao and Lei Xiao themselves ... if they are indeed the authors, rather than victims of internet fraudsters.