I think GP was referring to Montagnier's support of the water memory theory (a fraudulent theory made up to support homeopathy), rather than his comments on covid 19.
> In January 2009, Luc Montagnier, the Nobel Laureate virologist who led the team that discovered the human immunodeficiency virus (HIV), claimed (in a paper published in a journal that he set up, which seems to have avoided conventional peer review as it was accepted three days after submission) that the DNA of pathogenic bacteria and viruses massively diluted in water emit radio waves that he can detect.
[1] https://en.wikipedia.org/wiki/Water_memory#Other_scientists
Looks like he'd gone that route well before any of the COVID-19 stuff.
Here they show pictures supposedly in support of water structure.
Quite a bit of work in the area.
Not the most ringing endorsement.