Anthony Joshua had admitted he wanted to crack Jarrell Miller in the jaw and says he “does not deserve” to be in a boxing ring.
Heavyweight Miller, 30, failed three drugs tests and sparked fury among AJ’s camp.
Promoter Eddie Hearn described it as: “the most extensive case of cheating in this sport we have ever seen.”
And WBA, IBF and WBO heavyweight king Joshua, 29, agreed with his promoter’s stance.
He said: “I don’t want to talk too much about the situation with Jarrell Miller, because it is not in my character to knock a man when he is down.
“There are a lot of things he has said previously, at press conferences and in the build-up – and I wanted to crack him in his jaw.
“But I know when you are in a position, you have to lead by example, and I knew that was not the right thing to do.
“But the lesson to learn is that karma works in various ways – what goes around will come back around.
“I feel he has taken fate and his own blessings out of his own hands.
“Sometimes, be respectful – I know it is a fight – but be respectful, be appreciative and lead by example. What he has done is not lead by example.”
Joshua, 28, is currently yet to announce a new opponent in the next 48 to 72 hours.
The fight is scheduled to take place in Madison Square Garden in New York on June 1.
He added: “Cheats will get found out and hustlers and hard workers will always rise to the top.
“Good luck to Jarrell Miller with whatever he does in his life.
“But he does not deserve to be in a ring with me or any other heavyweight right now.
“I don’t know what the future holds, that is not up to me, that is up to the governing bodies but they will make the right call.”