Suspended Virginia Tech linebacker Isi Etute told cops he beat the hell out of a 40-year-old after the man had catfished him ... this according to prosecutors.
Officials made the stunning revelation in a Virginia courtroom Wednesday ... explaining Etute broke it all down for cops during their murder investigation days ago.
Prosecutors say Etute told the cops he had matched with a person named "Angie" on Tinder believing she was a woman -- and had met up with her for oral sex on April 10.
Officials say Etute then told cops he and "Angie" set up another date on May 31, but when he discovered there that she was actually a man -- the football player attacked.