A very early genomic sequence of SARS-CoV-2 was posted by Chinese researchers, then removed (probably because of Chinese government pressure). However, a few western researchers grabbed the sequence before it was removed and analyzed it. As well as viral sequence, the sample had raccoon dog DNA sequences associated with it (as contaminants), implying that this extremely early virus sample came from raccoon dogs. It’s known that raccoon dogs were kept in the wet market that’s been implicated in very early COVID19 transmission, and raccoon dogs are highly susceptible to infection with SARS-CoV-2, so it’s a consistent story.