12:27 PM PT -- 9/14 -- A rep for the Grady County Jail -- where Joe claims the sexual assault happened -- had no comment. However, a law enforcement source at the jail denies the allegations, claiming there are cameras all around the facility and saying it's Joe's character to make things up.
7:12 AM PT -- We reached out to our federal prison sources about Joe's claims, who tell us, "there was no such assault."
Joe Exotic has submitted a 257-page case to Donald Trump -- arguing various reasons why he should be pardoned from his 22-year murder-for-hire sentence -- claiming he was sexually assaulted behind bars.
Joe included a letter he sent to Donald Trump Jr. in his documents, in which he claims, "I have been sexually assaulted by jail staff, beat up and tied in a chair to the point the skin came off my arms." He goes on to say, "please be my hero ... my hands are damaged from the abuse in jail so I'm sorry for the soppy (sic) writing and spelling" and adding this ... "#TrumpJr.2024." We reached out to the prison for comment ... so far, no word back.
Joe says he fears he'll die in prison before his scheduled 2037 release, because his health is compromised because of various medical issues, including anemia and common variable immune deficiency.
Joe submitted various character references, including one from Kerri Walker, whose cousin worked at the zoo. She makes an appeal to Trump, saying Joe got a raw deal, just like Trump did with the "grab-'em-by-the-p***y" tape.
Joe goes on to say he never tried to kill Carole Baskin, and that all the so-called threats he made against her were just "hyperbole." His lawyers say in the docs, obtained by TMZ, the "threats" were "simply another aspect of his showmanship ... Joe's jokes, at most, in bad taste, were merely jokes."
Joe also insists he's been "railroaded and betrayed, repeatedly" ... blaming Jeff Lowe, the judge and others. He says the $3k he forked over to the alleged hitman was not to pay for a hit ... it was to get the guy out of his hair.
Joe also believes one of the reasons he was convicted was because of anti-gay sentiments.
He admits to shooting some tigers that were ill, saying that was the humane way of euthanizing them.
And Joe's husband, Dillon Passage, wrote a letter saying Joe saved him from addiction. Passage wrote ... "I see a sweet, big heart man, with good intentions, who took a few steps down a dark road, and he's just waiting to be pulled out of it."
Joe makes his plea to President Trump, saying, "Allow me to make you proud, to make America proud, to make the world proud. Be my hero please."
TMZ broke the story ... Joe's team is flying to D.C. Wednesday where Eric Love, who's leading the charge for Joe, will present the pardon application to someone he knows in The White House.