Matt Mitrione was suspended indefinitely by the UFC on Monday, hours after the heavyweight fighter and former NFL defensive lineman called transgender MMA competitor Fallon Fox “a lying, sick, sociopathic, disgusting freak” in an interview.

“The UFC was appalled by the transphobic comments made by heavyweight Matt Mitrione today in an interview on the 'MMA Hour,'” the UFC said in a statement Monday evening. “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.”

Mitrione’s comments came at the end of an interview on SB Nation’s “MMA Hour” on Monday, a show hosted by Fuel TV’s Ariel Helwani. His comments about Fox — who was born a man and underwent gender reassignment surgery in 2006 — came unsolicited during the end of the interview.