Sources close to production tell us ... yes, that was a joint in her hand as she hugged Scott Disick. We're told producers didn't mind Khloe shooting scenes with it because it was natural -- she was having a good time with the fam in Costa Rica, and sometimes ganja happens.
For the record ... cannabis is decriminalized for personal use in CR.
Translation: Smoke 'em if ya got 'em. And Khloe definitely had 'em. Pura Vida!