Wladimir Klitschko has compared Tyson Fury to Hitler, and believes his controversial comments should lead to a suspension.
In a video published on YouTube last month, defending WBA and WBO heavyweight champion Fury spoke on rape, bestiality and the Jewish faith.
He has also previously been accused of sexism and homophobia, and voiced extreme views on paedophilia.
The Campaign Against Antisemitism called for him to be banned for his "offensive and racist remarks" and made a complaint to the British Boxing Board of Control. Klitschko - who faces Fury in a rematch at the Manchester Arena on July 9 - has echoed those calls, regardless of the apology his opponent issued via a statement.
He lost his first fight in 11 years when Fury earned a surprise unanimous decision victory against him in Düsseldorf in November, and speaking from his training camp in the Tyrolean Alps in Austria, he said: "I'm fighting a guy who can't hold his mouth on certain things.
"I was in shock at his statements about women, the gay community, and when he got to the Jewish people he sounded like Hitler. The man is an imbecile. Seriously.
"You cannot put it all together as a representation of the sport of boxing. He's an imbecile champion.
"It puts the world of boxing in the wrong spot. He represents not just himself, but the sanctioning bodies, a lot of boxing fans in general, it's not just about him and he needs to understand but he obviously doesn't. All the stupidity that comes out of his mouth...
"Especially in this crazy world when we can see all that's going on, we don't need someone having this stage and bringing hate to Jewish people, I can't accept."
Klitschko continued: "As I said, he sounds like Hitler, I cannot accept it and I don't accept. The man is probably mentally sick.
"We cannot have a champion like that. Either he needs to be shut up or shut down in the ring, or just suspended, because you cannot create more hate.
"Friction creates friction, the more hate you bring out there - with women, the gay community and Jewish people - what next is he going to say?"
For all that there was little from the first fight that suggested Klitschko is capable of succeeding in next month's rematch, the 40-year-old remains adamant he is certain of victory.
He also dismissed suggestions that, as Fury said, IBF titlist Anthony Joshua is a "paper champion", that November's defeat meant he needed to change his preparation, and that that fight led to him considering retirement.
"It's not just British fans I'll be doing a favour when I beat him, it'll be for Klitschko fans and boxing fans in general," said the 40-year-old.
"It's just something we don't need in this world, it's beyond boxing. I'm totally not on the same page as him.
"There's a lot of BS coming out of his mouth and I'm not buying it.
"I'm really happy that Joshua won the fight, I think it's good for boxing that Joshua is world champion and I'm happy for him.
"It's an exciting time and there's nothing wrong with Joshua having the IBF belt. I have no doubt that eventually (a Joshua fight) can happen, but there's nothing I'm looking at beyond Tyson Fury.
"My routine will remain the same as it has been in the past years.
"There was a lack of punches thrown and whatever it was I'm going to fix it on July 9.
"I never thought about retirement. Because there was nothing leading me to that. I don't actually believe what happened.
"Fury won the fight but I don't feel defeated. I know how to fix it and we are capable of doing that.
"I've had three defeats before and after each defeat I came back stronger.
"My preparation was not bad. We accomplished what we needed to accomplish. If you control your mind that's it. I just need to tighten a couple of screws."