The most likely theory of artificial origin is that SARS-CoV-2 was deliberately created as a chimera of two natural sarbecoviruses with a human-designed furin cleavage site between them. The WIV proposed to undertake this research in collaboration with Ralph Baric in the DEFUSE proposal, as a step towards his goal of a pan-coronavirus vaccine. DARPA declined to fund the proposal, in part due to safety concerns. Zhengli Shi had the technical knowledge to perform the work alone at the WIV, although no specific evidence has yet emerged that she did so.

https://theintercept.com/2021/09/23/coronavirus-research-gra...

That said, Montagnier appears to have speculated that SARS-CoV-2 contains genetic information from HIV. That seems almost surely false, since the sequences he cited occur frequently in many organisms.

https://apnews.com/article/conspiracy-theories-iran-only-on-...