Leon Lawson, Andre Dirrell's trainer and uncle, has been "suspended indefinitely" by the World Boxing Council.
Lawson attacked his nephew's opponent Jose Uzcategui in the wake of the Venezuelan's controversial disqualification for punching Dirrell after the bell in Saturday's IBF super middleweight clash in Maryland.
An unsuspecting Uzcategui was caught flush on the jaw by Lawson, who then followed up with two more punches before fleeing the scene.
"The WBC is suspending indefinitely Mr. Leon Lawson from participating in any WBC sanctioned fight in any form or manner," said a statement on the organisation's website.
"The actions which have been seen all over the world, in which Mr. Lawson attacks and punches with bare fists fighter Jose Uzcategui, have created regrettable damages to our sport.
"The WBC rejects any form of foul play, aggression and behaviour.
"We will seek a meeting with Mr. Lawson to offer several forms of help to address this grave situation."
Lawson is still being hunted by the police and faces up to 25 years in prison after being charged with first and second degree assault for the attack.
Dirrell, whose two career defeats were at the hands of British duo James DeGale and Carl Froch, previously spent 21 months out of the ring after being caught by an illegal blow thrown by Arthur Abraham in their Super Six clash seven years ago.
The 2004 Olympic bronze medallist has issued an apology for his uncle's behaviour.
"I'm sorry for what my coach has done. My coach is my family, my uncle, and he was worried," said Dirrell. "He cares for me. He loves me. Please forgive him."