The only article that I can find that actually tries to levy complaints of obstruction is this one from the NYT[0]. However, several of the WHO investigators quoted have gone on Twitter accusing the NYT of twisting their words[1]. Makes me pretty doubtful that there was any obstruction.
On one side we have a country with half a million cases that has since December been accusing China with "coverups" without materializing much evidence, despite document leaks and now an international investigation. On the other side we have a country with orders of magnitude fewer total and per capita cases, whose case demographics have matched up with numbers from other countries, and whose export numbers in neighboring countries has also been consistent with their reported numbers. At this point if there was some sort of obstruction or coverup the Whitehouse would have a smoking gun by now.
Other comments here talking about the "lab origin" theory pretty much hinge on theological logic. "Well it could come from a lab, and there's no proof yet that it didn't, so I have faith". It isn't Bayesian reasoning if you don't bring up rigorous statistics to prove your point.
[0] https://www.nytimes.com/2021/02/12/world/asia/china-world-he...
[1] https://www.moonofalabama.org/2021/02/caught-in-the-act-new-...