Model SueLyn Medeiros -- the hottest DUI arrestee of all time -- tells TMZ, the sex tape that just hit the Internet featuring her and her BF was jacked from her computer without permission ... and now, she's gearing up to sue.
She has no idea how it happened -- but SueLyn claims she has already contacted a lawyer, and plans to drop the legal hammer on the website that published the video.
SueLyn tells us, "I am very upset and angry with all this and the way it was released and what was said about me ... I am in a loving relationship, and me and my boyfriend took a few personal private videos doing things I'm sure every couple does."
She adds, "Someone stole these files from us ... My family is very upset and disappointed. My mother can't stop crying. I want justice."
Attempts to reach the people behind the site were unsuccessful.