Originally Posted by BullMcGiveny
Baron Zemo, actually. Was he affiliated with HYDRA at the time? I don't remember.
As for the exact date of Cap's disappearance, I think it is in February 1945. There was an auction for the props from the movie a while ago, and the catalogue features a document pertaining to Zola's capture dated February 1945.
Could've sworn he was but I don't know anymore since they've retconned a bunch of stuff regarding Cap's comic WW2 history.