O.T. Genasis Gives Side-Eye Over YouTube Pulling His Keyshia Cole Cover

O.T. Genasis' hilariously off-key cover of Keyshia Cole's "Love" ballad is a viral sensation ... so he's determined to find out who got it yanked from YouTube ... and put 'em on blast.

We got O.T. at LAX Wednesday and asked why his pitchy new party anthem, "Never Knew," has vanished ... and he's nothing if not suspicious. Signs point to Keyshia as a likely suspect, but the singer's recently admitted she likes the cover and thinks O.T.'s take is funny.

So, whodunnit?? The rapper might not know for sure just yet ... but his savage side-eye in this clip speaks volumes.

His investigation seems to be all in good fun, though, and the rapper tells us he'd love to collab with Cole ... if it's true she's a fan of his comedic reboot. Still, he warns ... if Keyshia turns out to be the mystery hater, he'll let the world know.

Despite the YouTube deletion ... Genasis is free to perform "Never Knew" live ... as he did Tuesday night at Teyana Taylor's ugly sweater party.

Gotta say, we can see why it's a hit -- but don't sleep on the original.