UFC suspended the contract of Matt Mitrione on Monday after the heavyweight made disparaging remarks about transgender female fighter Fallon Fox.
"She's not a he, he's a he," the 34-year-old Mitrione said earlier Monday on the Internet-based talk show "MMA Hour."
"He's chromosomally a man. He had a gender change, not a sex change. He's still a man. He was a man for 31 years, 31 years. That's a couple years younger than I am. He's a man. Six years of taking performance de-hancing drugs you think is going to change all that? That's ridiculous.
"That is a lying, sick, sociopathic, disgusting freak. And I mean that."
Fox was recently cleared by the Florida State Boxing Commission of any wrongdoing after failing to disclose that she was born a male on her application for an MMA fighting license.
The 37-year-old Fox revealed her original gender to SI.com on March 4, two days after she knocked out Ericka Newsome 39 seconds into their Championship Fighting Alliance featherweight quarterfinal bout in Coral Gables, Fla.
"The UFC was appalled by the transphobic comments made by heavyweight Matt Mitrione [on Monday] in an interview on the 'MMA Hour,' " the promotion said on its website.
"The organization finds Mr. Mitrione's comments offensive and wholly unacceptable and -- as a direct result of this significant breach of the UFC's code of conduct -- Mr. Mitrione's UFC contract has been suspended and the incident is being investigated.
"The UFC is a friend and ally of the LGBT community, and expects and requires all 450 of its athletes to treat others with dignity and respect."
Mitrione, a former NFL player who was given the nickname "Meathead" during his participation on Season 10 of "The Ultimate Fighter" by then-coach Rashad Evans, improved to 6-2 Saturday with a first-round knockout of Phil De Fries in Stockholm, Sweden.